Merge pull request #22107 from Ericson2314/cross-tepid

Somewhat saner cross-compiling through bootstrapping

doc/cross-compilation.xml

@@ -0,0 +1,153 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-cross">
+
+<title>Cross-compilation</title>
+
+<section xml:id="sec-cross-intro">
+  <title>Introduction</title>
+  <para>
+    "Cross-compilation" means compiling a program on one machine for another type of machine.
+    For example, a typical use of cross compilation is to compile programs for embedded devices.
+    These devices often don't have the computing power and memory to compile their own programs.
+    One might think that cross-compilation is a fairly niche concern, but there are advantages to being rigorous about distinguishing build-time vs run-time environments even when one is developing and deploying on the same machine.
+    Nixpkgs is increasingly adopting this opinion in that packages should be written with cross-compilation in mind, and nixpkgs should evaluate in a similar way (by minimizing cross-compilation-specific special cases) whether or not one is cross-compiling.
+  </para>
+
+  <para>
+    This chapter will be organized in three parts.
+    First, it will describe the basics of how to package software in a way that supports cross-compilation.
+    Second, it will describe how to use Nixpkgs when cross-compiling.
+    Third, it will describe the internal infrastructure supporting cross-compilation.
+  </para>
+</section>
+
+<!--============================================================-->
+
+<section xml:id="sec-cross-packaging">
+  <title>Packing in a cross-friendly manner</title>
+
+  <section>
+    <title>Platform parameters</title>
+    <para>
+      The three GNU Autoconf platforms, <wordasword>build</wordasword>, <wordasword>host</wordasword>, and <wordasword>cross</wordasword>, are historically the result of much confusion.
+      <link xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html" /> clears this up somewhat but there is more to be said.
+      An important advice to get out the way is, unless you are packaging a compiler or other build tool, just worry about the build and host platforms.
+      Dealing with just two platforms usually better matches people's preconceptions, and in this case is completely correct.
+    </para>
+    <para>
+      In Nixpkgs, these three platforms are defined as attribute sets under the names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>, and <literal>targetPlatform</literal>.
+      All are guaranteed to contain at least a <varname>platform</varname> field, which contains detailed information on the platform.
+      All three are always defined at the top level, so one can get at them just like a dependency in a function that is imported with <literal>callPackage</literal>:
+      <programlisting>{ stdenv, buildPlatform, hostPlatform, fooDep, barDep, .. }: ...</programlisting>
+    </para>
+    <warning><para>
+      These platforms should all have the same structure in all scenarios, but that is currently not the case.
+      When not cross-compiling, they will each contain a <literal>system</literal> field with a short 2-part, hyphen-separated summering string name for the platform.
+      But, when when cross compiling, <literal>hostPlatform</literal> and <literal>targetPlatform</literal> may instead contain <literal>config</literal> with a fuller 3- or 4-part string in the manner of LLVM.
+      We should have all 3 platforms always contain both, and maybe give <literal>config</literal> a better name while we are at it.
+    </para></warning>
+    <variablelist>
+      <varlistentry>
+        <term><varname>buildPlatform</varname></term>
+        <listitem><para>
+          The "build platform" is the platform on which a package is built.
+          Once someone has a built package, or pre-built binary package, the build platform should not matter and be safe to ignore.
+        </para></listitem>
+      </varlistentry>
+      <varlistentry>
+        <term><varname>hostPlatform</varname></term>
+        <listitem><para>
+          The "host platform" is the platform on which a package is run.
+          This is the simplest platform to understand, but also the one with the worst name.
+        </para></listitem>
+      </varlistentry>
+      <varlistentry>
+        <term><varname>targetPlatform</varname></term>
+        <listitem>
+          <para>
+            The "target platform" is black sheep.
+            The other two intrinsically apply to all compiled software—or any build process with a notion of "build-time" followed by "run-time".
+            The target platform only applies to programming tools, and even then only is a good for for some of them.
+            Briefly, GCC, Binutils, GHC, and certain other tools are written in such a way such that a single build can only compiler code for a single platform.
+            Thus, when building them, one must think ahead about what platforms they wish to use the tool to produce machine code for, and build binaries for each.
+          </para>
+          <para>
+            There is no fundamental need to think about the target ahead of time like this.
+            LLVM, for example, was designed from the beginning with cross-compilation in mind, and so a normal LLVM binary will support every architecture that LLVM supports.
+            If the tool supports modular or pluggable backends, one might imagine specifying a <emphasis>set</emphasis> of target platforms / backends one wishes to support, rather than a single one.
+          </para>
+          <para>
+            The biggest reason for mess, if there is one, is that many compilers have the bad habit a build process that builds the compiler and standard library/runtime together.
+            Then the specifying target platform is essential, because it determines the host platform of the standard library/runtime.
+            Nixpkgs tries to avoid this where possible too, but still, because the concept of a target platform is so ingrained now in Autoconf and other tools, it is best to support it as is.
+            Tools like LLVM that don't need up-front target platforms can safely ignore it like normal packages, and it will do no harm.
+          </para>
+          </listitem>
+      </varlistentry>
+    </variablelist>
+    <note><para>
+      If you dig around nixpkgs, you may notice there is also <varname>stdenv.cross</varname>.
+      This field defined as <varname>hostPlatform</varname> when the host and build platforms differ, but otherwise not defined at all.
+      This field is obsolete and will soon disappear—please do not use it.
+    </para></note>
+  </section>
+
+  <section>
+    <title>Specifying Dependencies</title>
+    <para>
+      As mentioned in the introduction to this chapter, one can think about a build time vs run time distinction whether cross-compiling or not.
+      In the case of cross-compilation, this corresponds with whether a derivation running on the native or foreign platform is produced.
+      An interesting thing to think about is how this corresponds with the three Autoconf platforms.
+      In the run-time case, the depending and depended-on package simply have matching build, host, and target platforms.
+      But in the build-time case, one can imagine "sliding" the platforms one over.
+      The depended-on package's host and target platforms (respectively) become the depending package's build and host platforms.
+      This is the most important guiding principle behind cross-compilation with Nixpkgs, and will be called the <wordasword>sliding window principle</wordasword>.
+      In this manner, given the 3 platforms for one package, we can determine the three platforms for all its transitive dependencies.
+    </para>
+    <note><para>
+      The depending package's target platform is unconstrained by the sliding window principle, which makes sense in that one can in principle build cross compilers targeting arbitrary platforms.
+    </para></note>
+    <warning><para>
+      From the above, one would surmise that if a package is being built with a <literal>(build, host, target)</literal> platform triple of <literal>(foo, bar, bar)</literal>, then its build-time dependencies would have a triple of <literal>(foo, foo, bar)</literal>, and <emphasis>those packages'</emphasis> build-time dependencies would have triple of <literal>(foo, foo, foo)</literal>.
+      In other words, it should take two "rounds" of following build-time dependency edges before one reaches a fixed point where, by the sliding window principle, the platform triple no longer changes.
+      Unfortunately, at the moment, we do <emphasis>not</emphasis> implement this correctly, and after only one round of following build-time dependencies is the fixed point reached, with target incorrectly kept different than the others.
+    </para></warning>
+    <para>
+      How does this work in practice? Nixpkgs is now structured so that build-time dependencies are taken from from <varname>buildPackages</varname>, whereas run-time dependencies are taken from the top level attribute set.
+      For example, <varname>buildPackages.gcc</varname> should be used at build time, while <varname>gcc</varname> should be used at run time.
+      Now, for most of Nixpkgs's history, there was no <varname>buildPackages</varname>, and most packages have not been refactored to use it explicitly.
+      Instead, one can use the four attributes used for specifying dependencies as documented in <link linkend="ssec-stdenv-attributes" />.
+      We "splice" together the run-time and build-time package sets with <varname>callPackage</varname>, and then <varname>mkDerivation</varname> for each of four attributes pulls the right derivation out.
+      This splicing can be skipped when not cross compiling as the package sets are the same, but is a bit slow for cross compiling.
+      Because of this, a best-of-both-worlds solution is in the works with no splicing or explicit access of <varname>buildPackages</varname> needed.
+      For now, feel free to use either method.
+    </para>
+  </section>
+
+</section>
+
+<!--============================================================-->
+
+<section xml:id="sec-cross-usage">
+  <title>Cross-building packages</title>
+  <para>
+    To be written.
+    This is basically unchanged so see the old wiki for now.
+  </para>
+</section>
+
+<!--============================================================-->
+
+<section xml:id="sec-cross-infra">
+  <title>Cross-compilation infrastructure</title>
+  <para>To be written.</para>
+  <note><para>
+    If one explores nixpkgs, they will see derivations with names like <literal>gccCross</literal>.
+    Such <literal>*Cross</literal> derivations is a holdover from before we properly distinguished between the host and target platforms
+    —the derivation with "Cross" in the name covered the <literal>build = host != target</literal> case, while the other covered the <literal>host = target</literal>, with build platform the same or not based on whether one was using its <literal>.nativeDrv</literal> or <literal>.crossDrv</literal>.
+    This ugliness will disappear soon.
+  </para></note>
+</section>
+
+</chapter>

doc/manual.xml

@@ -13,6 +13,7 @@
   <xi:include href="quick-start.xml" />
   <xi:include href="stdenv.xml" />
   <xi:include href="multiple-output.xml" />
+  <xi:include href="cross-compilation.xml" />
   <xi:include href="configuration.xml" />
   <xi:include href="functions.xml" />
   <xi:include href="meta.xml" />

doc/stdenv.xml

@@ -194,34 +194,53 @@ genericBuild
     tools.</para></listitem>
   </varlistentry>
 
+</variablelist>
+
+<variablelist>
+  <title>Variables specifying dependencies</title>
+
+  <varlistentry>
+    <term><varname>nativeBuildInputs</varname></term>
+    <listitem><para>
+      A list of dependencies used by the new derivation at <emphasis>build</emphasis>-time.
+      I.e. these dependencies should not make it into the package's runtime-closure, though this is currently not checked.
+      For each dependency <replaceable>dir</replaceable>, the directory <filename><replaceable>dir</replaceable>/bin</filename>, if it exists, is added to the <envar>PATH</envar> environment variable.
+      Other environment variables are also set up via a pluggable mechanism.
+      For instance, if <varname>buildInputs</varname> contains Perl, then the <filename>lib/site_perl</filename> subdirectory of each input is added to the <envar>PERL5LIB</envar> environment variable.
+      See <xref linkend="ssec-setup-hooks"/> for details.
+    </para></listitem>
+  </varlistentry>
+
   <varlistentry>
     <term><varname>buildInputs</varname></term>
-    <listitem><para>A list of dependencies used by
+    <listitem><para>
-    <literal>stdenv</literal> to set up the environment for the build.
+      A list of dependencies used by the new derivation at <emphasis>run</emphasis>-time.
-    For each dependency <replaceable>dir</replaceable>, the directory
+      Currently, the build-time environment is modified in the exact same way as with <varname>nativeBuildInputs</varname>.
-    <filename><replaceable>dir</replaceable>/bin</filename>, if it
+      This is problematic in that when cross-compiling, foreign executables can clobber native ones on the <envar>PATH</envar>.
-    exists, is added to the <envar>PATH</envar> environment variable.
+      Even more confusing is static-linking.
-    Other environment variables are also set up via a pluggable
+      A statically-linked library should be listed here because ultimately that generated machine code will be used at run-time, even though a derivation containing the object files or static archives will only be used at build-time.
-    mechanism.  For instance, if <varname>buildInputs</varname>
+      A less confusing solution to this would be nice.
-    contains Perl, then the <filename>lib/site_perl</filename>
+    </para></listitem>
-    subdirectory of each input is added to the <envar>PERL5LIB</envar>
+  </varlistentry>
-    environment variable.  See <xref linkend="ssec-setup-hooks"/> for
+
-    details.</para></listitem>
+
+  <varlistentry>
+    <term><varname>propagatedNativeBuildInputs</varname></term>
+    <listitem><para>
+      Like <varname>nativeBuildInputs</varname>, but these dependencies are <emphasis>propagated</emphasis>:
+      that is, the dependencies listed here are added to the <varname>nativeBuildInputs</varname> of any package that uses <emphasis>this</emphasis> package as a dependency.
+      So if package Y has <literal>propagatedBuildInputs = [X]</literal>, and package Z has <literal>buildInputs = [Y]</literal>, then package X will appear in Z’s build environment automatically.
+    </para></listitem>
   </varlistentry>
 
   <varlistentry>
     <term><varname>propagatedBuildInputs</varname></term>
-    <listitem><para>Like <varname>buildInputs</varname>, but these
+    <listitem><para>
-    dependencies are <emphasis>propagated</emphasis>: that is, the
+      Like <varname>buildInputs</varname>, but propagated just like <varname>propagatedNativeBuildInputs</varname>.
-    dependencies listed here are added to the
+      This inherits <varname>buildInputs</varname>'s flaws of clobbering native executables when cross-compiling and being confusing for static linking.
-    <varname>buildInputs</varname> of any package that uses
+    </para></listitem>
-    <emphasis>this</emphasis> package as a dependency.  So if package
-    Y has <literal>propagatedBuildInputs = [X]</literal>, and package
-    Z has <literal>buildInputs = [Y]</literal>, then package X will
-    appear in Z’s build environment automatically.</para></listitem>
   </varlistentry>
 
-
 </variablelist>
 
 <variablelist>
@@ -1607,4 +1626,3 @@ Arch Wiki</link>.
 </section>
 
 </chapter>
-

nixos/doc/manual/release-notes/rl-1703.xml

@@ -30,6 +30,15 @@ has the following highlights: </para>
 following incompatible changes:</para>
 
 <itemizedlist>
+  <listitem>
+    <para>
+      Cross compilation has been rewritten. See the nixpkgs manual for
+      details. The most obvious breaking change is that derivations absent a
+      <literal>.nativeDrv</literal> or <literal>.crossDrv</literal> are now
+      cross by default, not native.
+    </para>
+  </listitem>
+
   <listitem>
     <para>
       <literal>stdenv.overrides</literal> is now expected to take <literal>self</literal>

pkgs/build-support/cc-wrapper/default.nix

@@ -281,9 +281,6 @@ stdenv.mkDerivation {
   crossAttrs = {
     shell = shell.crossDrv + shell.crossDrv.shellPath;
     libc = stdenv.ccCross.libc;
-    coreutils = coreutils.crossDrv;
-    binutils = binutils.crossDrv;
-    cc = cc.crossDrv;
     #
     # This is not the best way to do this. I think the reference should be
     # the style in the gcc-cross-wrapper, but to keep a stable stdenv now I

pkgs/development/compilers/ghc/head.nix

@@ -1,5 +1,6 @@
 { stdenv, fetchgit, bootPkgs, perl, gmp, ncurses, libiconv, binutils, coreutils
-, autoconf, automake, happy, alex, python3, crossSystem, selfPkgs, cross ? null
+, autoconf, automake, happy, alex, python3, buildPlatform, targetPlatform
+, selfPkgs, cross ? null
 }:
 
 let
@@ -68,9 +69,9 @@ in stdenv.mkDerivation (rec {
 
   passthru = {
     inherit bootPkgs;
-  } // stdenv.lib.optionalAttrs (crossSystem != null) {
+  } // stdenv.lib.optionalAttrs (targetPlatform != buildPlatform) {
     crossCompiler = selfPkgs.ghc.override {
-      cross = crossSystem;
+      cross = targetPlatform;
       bootPkgs = selfPkgs;
     };
   };

pkgs/development/libraries/openssl/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, perl
+{ stdenv, fetchurl, buildPackages, perl
 , withCryptodev ? false, cryptodevHeaders
 , enableSSL2 ? false }:
 
@@ -76,7 +76,7 @@ let
 
     postFixup = ''
       # Check to make sure the main output doesn't depend on perl
-      if grep -r '${perl}' $out; then
+      if grep -r '${buildPackages.perl}' $out; then
         echo "Found an erroneous dependency on perl ^^^" >&2
         exit 1
       fi

pkgs/os-specific/gnu/default.nix

@@ -3,7 +3,8 @@
 args@{ fetchgit, stdenv, autoconf, automake, automake111x, libtool
 , texinfo, glibcCross, hurdPartedCross, libuuid, samba
 , gccCrossStageStatic, gccCrossStageFinal
-, forceNativeDrv, forceSystem, newScope, platform, config, crossSystem
+, forcedNativePackages, forceSystem, newScope, platform, config
+, targetPlatform, buildPlatform
 , overrides ? {} }:
 
 with args;
@@ -12,25 +13,25 @@ let
   callPackage = newScope gnu;
 
   gnu = {
-    hurdCross = forceNativeDrv (callPackage ./hurd {
+    hurdCross = forcedNativePackages.callPackage ./hurd {
       inherit fetchgit stdenv autoconf libtool texinfo
         glibcCross hurdPartedCross;
       inherit (gnu) machHeaders mig;
       libuuid = libuuid.crossDrv;
       automake = automake111x;
       headersOnly = false;
-      cross = assert crossSystem != null; crossSystem;
+      cross = assert targetPlatform != buildPlatform; targetPlatform;
       gccCross = gccCrossStageFinal;
-    });
+    };
 
-    hurdCrossIntermediate = forceNativeDrv (callPackage ./hurd {
+    hurdCrossIntermediate = forcedNativePackages.callPackage ./hurd {
       inherit fetchgit stdenv autoconf libtool texinfo glibcCross;
       inherit (gnu) machHeaders mig;
       hurdPartedCross = null;
       libuuid = null;
       automake = automake111x;
       headersOnly = false;
-      cross = assert crossSystem != null; crossSystem;
+      cross = assert targetPlatform != buildPlatform; targetPlatform;
 
       # The "final" GCC needs glibc and the Hurd libraries (libpthread in
       # particular) so we first need an intermediate Hurd built with the
@@ -42,7 +43,7 @@ let
       # libshouldbeinlibc.
       buildTarget = "libihash libstore libshouldbeinlibc";
       installTarget = "libihash-install libstore-install libshouldbeinlibc-install";
-    });
+    };
 
     hurdHeaders = callPackage ./hurd {
       automake = automake111x;
@@ -58,13 +59,13 @@ let
       hurd = null;
     };
 
-    libpthreadCross = forceNativeDrv (callPackage ./libpthread {
+    libpthreadCross = forcedNativePackages.callPackage ./libpthread {
       inherit fetchgit stdenv autoconf automake libtool glibcCross;
       inherit (gnu) machHeaders hurdHeaders;
       hurd = gnu.hurdCrossIntermediate;
       gccCross = gccCrossStageStatic;
-      cross = assert crossSystem != null; crossSystem;
+      cross = assert targetPlatform != buildPlatform; targetPlatform;
-    });
+    };
 
     # In theory GNU Mach doesn't have to be cross-compiled.  However, since it
     # has to be built for i586 (it doesn't work on x86_64), one needs a cross

pkgs/stdenv/adapters.nix

@@ -56,69 +56,59 @@ rec {
 
   # Return a modified stdenv that adds a cross compiler to the
   # builds.
-  makeStdenvCross = stdenv: cross: binutilsCross: gccCross: stdenv //
+  makeStdenvCross = stdenv: cross: binutilsCross: gccCross: stdenv // {
-    { mkDerivation = {name ? "", buildInputs ? [], nativeBuildInputs ? [],
-            propagatedBuildInputs ? [], propagatedNativeBuildInputs ? [],
-            selfNativeBuildInput ? false, ...}@args: let
 
-            # *BuildInputs exists temporarily as another name for
+    mkDerivation =
-            # *HostInputs.
+      { name ? "", buildInputs ? [], nativeBuildInputs ? []
+      , propagatedBuildInputs ? [], propagatedNativeBuildInputs ? []
+      , selfNativeBuildInput ? false, ...
+      } @ args:
 
-            # In nixpkgs, sometimes 'null' gets in as a buildInputs element,
+      let
-            # and we handle that through isAttrs.
+        # *BuildInputs exists temporarily as another name for
-            getNativeDrv = drv: drv.nativeDrv or drv;
+        # *HostInputs.
-            getCrossDrv = drv: drv.crossDrv or drv;
-            nativeBuildInputsDrvs = map getNativeDrv nativeBuildInputs;
-            buildInputsDrvs = map getCrossDrv buildInputs;
-            propagatedBuildInputsDrvs = map getCrossDrv propagatedBuildInputs;
-            propagatedNativeBuildInputsDrvs = map getNativeDrv propagatedNativeBuildInputs;
 
-            # The base stdenv already knows that nativeBuildInputs and
+        # The base stdenv already knows that nativeBuildInputs and
-            # buildInputs should be built with the usual gcc-wrapper
+        # buildInputs should be built with the usual gcc-wrapper
-            # And the same for propagatedBuildInputs.
+        # And the same for propagatedBuildInputs.
-            nativeDrv = stdenv.mkDerivation args;
+        nativeDrv = stdenv.mkDerivation args;
 
-            # Temporary expression until the cross_renaming, to handle the
+        # Temporary expression until the cross_renaming, to handle the
-            # case of pkgconfig given as buildInput, but to be used as
+        # case of pkgconfig given as buildInput, but to be used as
-            # nativeBuildInput.
+        # nativeBuildInput.
-            hostAsNativeDrv = drv:
+        hostAsNativeDrv = drv:
-                builtins.unsafeDiscardStringContext drv.nativeDrv.drvPath
+            builtins.unsafeDiscardStringContext drv.nativeDrv.drvPath
-                == builtins.unsafeDiscardStringContext drv.crossDrv.drvPath;
+            == builtins.unsafeDiscardStringContext drv.crossDrv.drvPath;
-            buildInputsNotNull = stdenv.lib.filter
+        buildInputsNotNull = stdenv.lib.filter
-                (drv: builtins.isAttrs drv && drv ? nativeDrv) buildInputs;
+            (drv: builtins.isAttrs drv && drv ? nativeDrv) buildInputs;
-            nativeInputsFromBuildInputs = stdenv.lib.filter hostAsNativeDrv buildInputsNotNull;
+        nativeInputsFromBuildInputs = stdenv.lib.filter hostAsNativeDrv buildInputsNotNull;
+      in
+        stdenv.mkDerivation (args // {
+          name = name + "-" + cross.config;
+          nativeBuildInputs = nativeBuildInputs
+            ++ nativeInputsFromBuildInputs
+            ++ [ gccCross binutilsCross ]
+            ++ stdenv.lib.optional selfNativeBuildInput nativeDrv
+              # without proper `file` command, libtool sometimes fails
+              # to recognize 64-bit DLLs
+            ++ stdenv.lib.optional (cross.config  == "x86_64-w64-mingw32") pkgs.file
+            ;
 
-            # We should overwrite the input attributes in crossDrv, to overwrite
+          # Cross-linking dynamic libraries, every buildInput should
-            # the defaults for only-native builds in the base stdenv
+          # be propagated because ld needs the -rpath-link to find
-            crossDrv = if cross == null then nativeDrv else
+          # any library needed to link the program dynamically at
-                stdenv.mkDerivation (args // {
+          # loader time. ld(1) explains it.
-                    name = name + "-" + cross.config;
+          buildInputs = [];
-                    nativeBuildInputs = nativeBuildInputsDrvs
+          propagatedBuildInputs = propagatedBuildInputs ++ buildInputs;
-                      ++ nativeInputsFromBuildInputs
+          propagatedNativeBuildInputs = propagatedNativeBuildInputs;
-                      ++ [ gccCross binutilsCross ]
-                      ++ stdenv.lib.optional selfNativeBuildInput nativeDrv
-                        # without proper `file` command, libtool sometimes fails
-                        # to recognize 64-bit DLLs
-                      ++ stdenv.lib.optional (cross.config  == "x86_64-w64-mingw32") pkgs.file
-                      ;
 
-                    # Cross-linking dynamic libraries, every buildInput should
+          crossConfig = cross.config;
-                    # be propagated because ld needs the -rpath-link to find
+        } // args.crossAttrs or {});
-                    # any library needed to link the program dynamically at
-                    # loader time. ld(1) explains it.
-                    buildInputs = [];
-                    propagatedBuildInputs = propagatedBuildInputsDrvs ++ buildInputsDrvs;
-                    propagatedNativeBuildInputs = propagatedNativeBuildInputsDrvs;
 
-                    crossConfig = cross.config;
+    inherit gccCross binutilsCross;
-                } // args.crossAttrs or {});
+    ccCross = gccCross;
-        in nativeDrv // {
+
-          inherit crossDrv nativeDrv;
+  };
-        };
-    } // {
-      inherit cross gccCross binutilsCross;
-      ccCross = gccCross;
-    };
 
 
   /* Modify a stdenv so that the specified attributes are added to

pkgs/stdenv/booter.nix

@@ -57,12 +57,17 @@ stageFuns: let
   # debugging purposes.
   folder = stageFun: finalSoFar: let
     args = stageFun finalSoFar;
-    stdenv = args.stdenv // {
+    args' = args // {
-      # For debugging
+      stdenv = args.stdenv // {
-      __bootPackages = finalSoFar;
+        # For debugging
+        __bootPackages = finalSoFar;
+      };
     };
-    args' = args // { inherit stdenv; };
   in
-    (if args.__raw or false then lib.id else allPackages) args';
+    if args.__raw or false
+    then args'
+    else allPackages ((builtins.removeAttrs args' ["selfBuild"]) // {
+      buildPackages = if args.selfBuild or true then null else finalSoFar;
+    });
 
 in lib.lists.fold folder {} withAllowCustomOverrides

pkgs/stdenv/cross/default.nix

@@ -1,10 +1,10 @@
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 }:
 
 let
   bootStages = import ../. {
-    inherit lib system platform overlays;
+    inherit lib localSystem overlays;
     crossSystem = null;
     # Ignore custom stdenvs when cross compiling for compatability
     config = builtins.removeAttrs config [ "replaceStdenv" ];
@@ -12,25 +12,28 @@ let
 
 in bootStages ++ [
 
-  # Build Packages.
+  # Build Packages
-  #
-  # For now, this is just used to build the native stdenv. Eventually, it
-  # should be used to build compilers and other such tools targeting the cross
-  # platform. Then, `forceNativeDrv` can be removed.
   (vanillaPackages: {
-    inherit system platform crossSystem config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = crossSystem;
+    inherit config overlays;
+    # Should be false, but we're trying to preserve hashes for now
+    selfBuild = true;
     # It's OK to change the built-time dependencies
     allowCustomOverrides = true;
     stdenv = vanillaPackages.stdenv // {
-      # Needed elsewhere as a hacky way to pass the target
-      cross = crossSystem;
       overrides = _: _: {};
     };
   })
 
-  # Run packages
+  # Run Packages
   (buildPackages: {
-    inherit system platform crossSystem config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = crossSystem;
+    targetPlatform = crossSystem;
+    inherit config overlays;
+    selfBuild = false;
     stdenv = if crossSystem.useiOSCross or false
       then let
           inherit (buildPackages.darwin.ios-cross {

pkgs/stdenv/custom/default.nix

@@ -1,12 +1,12 @@
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 }:
 
 assert crossSystem == null;
 
 let
   bootStages = import ../. {
-    inherit lib system platform crossSystem overlays;
+    inherit lib localSystem crossSystem overlays;
     # Remove config.replaceStdenv to ensure termination.
     config = builtins.removeAttrs config [ "replaceStdenv" ];
   };
@@ -15,7 +15,10 @@ in bootStages ++ [
 
   # Additional stage, built using custom stdenv
   (vanillaPackages: {
-    inherit system platform crossSystem config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = localSystem;
+    inherit config overlays;
     stdenv = config.replaceStdenv { pkgs = vanillaPackages; };
   })
 

pkgs/stdenv/darwin/default.nix

@@ -1,11 +1,12 @@
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 
 # Allow passing in bootstrap files directly so we can test the stdenv bootstrap process when changing the bootstrap tools
 , bootstrapFiles ? let
   fetch = { file, sha256, executable ? true }: import <nix/fetchurl.nix> {
     url = "http://tarballs.nixos.org/stdenv-darwin/x86_64/33f59c9d11b8d5014dfd18cc11a425f6393c884a/${file}";
-    inherit sha256 system executable;
+    inherit (localSystem) system;
+    inherit sha256 executable;
   }; in {
     sh      = fetch { file = "sh";    sha256 = "1rx4kg6358xdj05z0m139a0zn4f4zfmq4n4vimlmnwyfiyn4x7wk"; };
     bzip2   = fetch { file = "bzip2"; sha256 = "104qnhzk79vkbp2yi0kci6lszgfppvrwk3rgxhry842ly1xz2r7l"; };
@@ -18,6 +19,8 @@
 assert crossSystem == null;
 
 let
+  inherit (localSystem) system platform;
+
   libSystemProfile = ''
     (import "${./standard-sandbox.sb}")
   '';
@@ -98,7 +101,10 @@ in rec {
       };
 
     in {
-      inherit system platform crossSystem config overlays;
+      buildPlatform = localSystem;
+      hostPlatform = localSystem;
+      targetPlatform = localSystem;
+      inherit config overlays;
       stdenv = thisStdenv;
     };
 
@@ -316,7 +322,10 @@ in rec {
     stage3
     stage4
     (prevStage: {
-      inherit system crossSystem platform config overlays;
+      buildPlatform = localSystem;
+      hostPlatform = localSystem;
+      targetPlatform = localSystem;
+      inherit config overlays;
       stdenv = stdenvDarwin prevStage;
     })
   ];

pkgs/stdenv/default.nix

@@ -7,7 +7,7 @@
 { # Args just for stdenvs' usage
   lib
   # Args to pass on to the pkgset builder, too
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 } @ args:
 
 let
@@ -51,4 +51,4 @@ in
     "i686-cygwin" = stagesNative;
     "x86_64-cygwin" = stagesNative;
     "x86_64-freebsd" = stagesFreeBSD;
-  }.${system} or stagesNative
+  }.${localSystem.system} or stagesNative

pkgs/stdenv/freebsd/default.nix

@@ -1,8 +1,9 @@
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 }:
 
 assert crossSystem == null;
+let inherit (localSystem) system; in
 
 
 [
@@ -58,7 +59,10 @@ assert crossSystem == null;
   })
 
   (prevStage: {
-    inherit system crossSystem platform config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = localSystem;
+    inherit config overlays;
     stdenv = import ../generic {
       name = "stdenv-freebsd-boot-3";
       inherit system config;

pkgs/stdenv/generic/default.nix

@@ -115,7 +115,19 @@ let
     , sandboxProfile ? ""
     , propagatedSandboxProfile ? ""
     , ... } @ attrs:
-    let
+    let # Rename argumemnts to avoid cycles
+      buildInputs__ = buildInputs;
+      nativeBuildInputs__ = nativeBuildInputs;
+      propagatedBuildInputs__ = propagatedBuildInputs;
+      propagatedNativeBuildInputs__ = propagatedNativeBuildInputs;
+    in let
+      getNativeDrv = drv: drv.nativeDrv or drv;
+      getCrossDrv = drv: drv.crossDrv or drv;
+      nativeBuildInputs = map getNativeDrv nativeBuildInputs__;
+      buildInputs = map getCrossDrv buildInputs__;
+      propagatedBuildInputs = map getCrossDrv propagatedBuildInputs__;
+      propagatedNativeBuildInputs = map getNativeDrv propagatedNativeBuildInputs__;
+    in let
       pos' =
         if pos != null then
           pos

pkgs/stdenv/linux/default.nix

@@ -4,21 +4,23 @@
 # compiler and linker that do not search in default locations,
 # ensuring purity of components produced by it.
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 
-, bootstrapFiles ?
+, bootstrapFiles ? { # switch
-    if system == "i686-linux" then import ./bootstrap-files/i686.nix
+    "i686-linux" = import ./bootstrap-files/i686.nix;
-    else if system == "x86_64-linux" then import ./bootstrap-files/x86_64.nix
+    "x86_64-linux" = import ./bootstrap-files/x86_64.nix;
-    else if system == "armv5tel-linux" then import ./bootstrap-files/armv5tel.nix
+    "armv5tel-linux" = import ./bootstrap-files/armv5tel.nix;
-    else if system == "armv6l-linux" then import ./bootstrap-files/armv6l.nix
+    "armv6l-linux" = import ./bootstrap-files/armv6l.nix;
-    else if system == "armv7l-linux" then import ./bootstrap-files/armv7l.nix
+    "armv7l-linux" = import ./bootstrap-files/armv7l.nix;
-    else if system == "mips64el-linux" then import ./bootstrap-files/loongson2f.nix
+    "mips64el-linux" = import ./bootstrap-files/loongson2f.nix;
-    else abort "unsupported platform for the pure Linux stdenv"
+  }.${localSystem.system}
+    or (abort "unsupported platform for the pure Linux stdenv")
 }:
 
 assert crossSystem == null;
 
 let
+  inherit (localSystem) system platform;
 
   commonPreHook =
     ''
@@ -91,7 +93,10 @@ let
       };
 
     in {
-      inherit system platform crossSystem config overlays;
+      buildPlatform = localSystem;
+      hostPlatform = localSystem;
+      targetPlatform = localSystem;
+      inherit config overlays;
       stdenv = thisStdenv;
     };
 
@@ -246,7 +251,10 @@ in
   # dependency (`nix-store -qR') on bootstrapTools or the first
   # binutils built.
   (prevStage: {
-    inherit system crossSystem platform config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = localSystem;
+    inherit config overlays;
     stdenv = import ../generic rec {
       inherit system config;
 

pkgs/stdenv/linux/make-bootstrap-tools-cross.nix

@@ -55,11 +55,12 @@ let
     if toolsArch == "armv6l" then raspberrypiCrossSystem else
     if toolsArch == "armv7l" then armv7l-hf-multiplatform-crossSystem else null;
 
-  pkgs = pkgsFun ({inherit system;} // selectedCrossSystem);
+  pkgsUnspliced = pkgsFun ({inherit system;} // selectedCrossSystem);
+  pkgs = pkgsUnspliced.splicedPackages;
 
-  inherit (pkgs) stdenv nukeReferences cpio binutilsCross;
+  inherit (pkgsUnspliced.buildPackages) stdenv nukeReferences cpio binutilsCross;
 
-  glibc = pkgs.libcCross;
+  glibc = pkgs.libcCross.nativeDrv;
   bash = pkgs.bash.crossDrv;
   findutils = pkgs.findutils.crossDrv;
   diffutils = pkgs.diffutils.crossDrv;
@@ -71,7 +72,7 @@ let
   gnumake = pkgs.gnumake.crossDrv;
   patch = pkgs.patch.crossDrv;
   patchelf = pkgs.patchelf.crossDrv;
-  gcc = pkgs.gcc.cc.crossDrv;
+  gcc = pkgs.gcc.crossDrv.cc;
   gmpxx = pkgs.gmpxx.crossDrv;
   mpfr = pkgs.mpfr.crossDrv;
   zlib = pkgs.zlib.crossDrv;
@@ -86,17 +87,17 @@ in
 rec {
 
 
-  coreutilsMinimal = (pkgs.coreutils.override (args: {
+  coreutilsMinimal = pkgs.coreutils.override (args: {
     # We want coreutils without ACL/attr support.
     aclSupport = false;
     attrSupport = false;
     # Our tooling currently can't handle scripts in bin/, only ELFs and symlinks.
     singleBinary = "symlinks";
-  })).crossDrv;
+  });
 
-  tarMinimal = (pkgs.gnutar.override { acl = null; }).crossDrv;
+  tarMinimal = pkgs.gnutar.override { acl = null; };
 
-  busyboxMinimal = (pkgs.busybox.override {
+  busyboxMinimal = pkgs.busybox.override {
     useMusl = true;
     enableStatic = true;
     enableMinimal = true;
@@ -109,13 +110,13 @@ rec {
       CONFIG_TAR y
       CONFIG_UNXZ y
     '';
-  }).crossDrv;
+  };
 
   build =
 
     stdenv.mkDerivation {
       name = "stdenv-bootstrap-tools-cross";
-      crossConfig = stdenv.cross.config;
+      crossConfig = pkgsUnspliced.hostPlatform.config;
 
       buildInputs = [nukeReferences cpio binutilsCross];
 

pkgs/stdenv/native/default.nix

@@ -1,10 +1,11 @@
 { lib
-, system, platform, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays
 }:
 
 assert crossSystem == null;
 
 let
+  inherit (localSystem) system platform;
 
   shell =
     if system == "i686-freebsd" || system == "x86_64-freebsd" then "/usr/local/bin/bash"
@@ -134,7 +135,10 @@ in
 
   # First build a stdenv based only on tools outside the store.
   (prevStage: {
-    inherit system crossSystem platform config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = localSystem;
+    inherit config overlays;
     stdenv = makeStdenv {
       inherit (prevStage) cc fetchurl;
     } // { inherit (prevStage) fetchurl; };
@@ -143,7 +147,10 @@ in
   # Using that, build a stdenv that adds the ‘xz’ command (which most systems
   # don't have, so we mustn't rely on the native environment providing it).
   (prevStage: {
-    inherit system crossSystem platform config overlays;
+    buildPlatform = localSystem;
+    hostPlatform = localSystem;
+    targetPlatform = localSystem;
+    inherit config overlays;
     stdenv = makeStdenv {
       inherit (prevStage.stdenv) cc fetchurl;
       extraPath = [ prevStage.xz ];

pkgs/stdenv/nix/default.nix

@@ -9,9 +9,9 @@ assert crossSystem == null;
 bootStages ++ [
   (prevStage: let
     inherit (prevStage) stdenv;
-    inherit (stdenv) system platform;
   in {
-    inherit system platform crossSystem config;
+    inherit (prevStage) buildPlatform hostPlatform targetPlatform;
+    inherit config overlays;
 
     stdenv = import ../generic rec {
       inherit config;

pkgs/tools/misc/coreutils/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, perl, xz, gmp ? null
+{ lib, stdenv, buildPackages, fetchurl, perl, xz, gmp ? null
 , aclSupport ? false, acl ? null
 , attrSupport ? false, attr ? null
 , selinuxSupport? false, libselinux ? null, libsepol ? null
@@ -12,104 +12,101 @@ assert selinuxSupport -> libselinux != null && libsepol != null;
 
 with lib;
 
-let
+stdenv.mkDerivation rec {
-  self = stdenv.mkDerivation rec {
+  name = "coreutils-8.26";
-    name = "coreutils-8.26";
 
-    src = fetchurl {
+  src = fetchurl {
-      url = "mirror://gnu/coreutils/${name}.tar.xz";
+    url = "mirror://gnu/coreutils/${name}.tar.xz";
-      sha256 = "13lspazc7xkviy93qz7ks9jv4sldvgmwpq36ghrbrqpq93br8phm";
+    sha256 = "13lspazc7xkviy93qz7ks9jv4sldvgmwpq36ghrbrqpq93br8phm";
-    };
+  };
 
-    # FIXME needs gcc 4.9 in bootstrap tools
+  # FIXME needs gcc 4.9 in bootstrap tools
-    hardeningDisable = [ "stackprotector" ];
+  hardeningDisable = [ "stackprotector" ];
 
-    patches = optional stdenv.isCygwin ./coreutils-8.23-4.cygwin.patch;
+  patches = optional stdenv.isCygwin ./coreutils-8.23-4.cygwin.patch;
 
-    # The test tends to fail on btrfs and maybe other unusual filesystems.
+  # The test tends to fail on btrfs and maybe other unusual filesystems.
-    postPatch = optionalString (!stdenv.isDarwin) ''
+  postPatch = optionalString (!stdenv.isDarwin) ''
-      sed '2i echo Skipping dd sparse test && exit 0' -i ./tests/dd/sparse.sh
+    sed '2i echo Skipping dd sparse test && exit 0' -i ./tests/dd/sparse.sh
-      sed '2i echo Skipping cp sparse test && exit 0' -i ./tests/cp/sparse.sh
+    sed '2i echo Skipping cp sparse test && exit 0' -i ./tests/cp/sparse.sh
-      sed '2i echo Skipping rm deep-2 test && exit 0' -i ./tests/rm/deep-2.sh
+    sed '2i echo Skipping rm deep-2 test && exit 0' -i ./tests/rm/deep-2.sh
-      sed '2i echo Skipping du long-from-unreadable test && exit 0' -i ./tests/du/long-from-unreadable.sh
+    sed '2i echo Skipping du long-from-unreadable test && exit 0' -i ./tests/du/long-from-unreadable.sh
+  '';
+
+  outputs = [ "out" "info" ];
+
+  nativeBuildInputs = [ perl xz.bin ];
+  configureFlags =
+    optional (singleBinary != false)
+      ("--enable-single-binary" + optionalString (isString singleBinary) "=${singleBinary}")
+    ++ optional stdenv.isSunOS "ac_cv_func_inotify_init=no"
+    ++ optional withPrefix "--program-prefix=g";
+
+  buildInputs = [ gmp ]
+    ++ optional aclSupport acl
+    ++ optional attrSupport attr
+    ++ optionals stdenv.isCygwin [ autoconf automake114x texinfo ]   # due to patch
+    ++ optionals selinuxSupport [ libselinux libsepol ];
+
+  crossAttrs = {
+    buildInputs = [ gmp.crossDrv ]
+      ++ optional aclSupport acl.crossDrv
+      ++ optional attrSupport attr.crossDrv
+      ++ optionals selinuxSupport [ libselinux.crossDrv libsepol.crossDrv ]
+      ++ optional (stdenv.ccCross.libc ? libiconv)
+        stdenv.ccCross.libc.libiconv.crossDrv;
+
+    # Prevents attempts of running 'help2man' on cross-built binaries.
+    PERL = "missing";
+
+    # Works around a bug with 8.26:
+    # Makefile:3440: *** Recursive variable 'INSTALL' references itself (eventually).  Stop.
+    preInstall = ''
+      sed -i Makefile -e 's|^INSTALL =.*|INSTALL = ${buildPackages.coreutils}/bin/install -c|'
     '';
 
-    outputs = [ "out" "info" ];
+    postInstall = ''
+      rm $out/share/man/man1/*
+      cp ${buildPackages.coreutils}/share/man/man1/* $out/share/man/man1
+    '';
 
-    nativeBuildInputs = [ perl xz.bin ];
+    # Needed for fstatfs()
-    configureFlags =
+    # I don't know why it is not properly detected cross building with glibc.
-      optional (singleBinary != false)
+    configureFlags = [ "fu_cv_sys_stat_statfs2_bsize=yes" ];
-        ("--enable-single-binary" + optionalString (isString singleBinary) "=${singleBinary}")
+    doCheck = false;
-      ++ optional stdenv.isSunOS "ac_cv_func_inotify_init=no"
-      ++ optional withPrefix "--program-prefix=g";
-
-    buildInputs = [ gmp ]
-      ++ optional aclSupport acl
-      ++ optional attrSupport attr
-      ++ optionals stdenv.isCygwin [ autoconf automake114x texinfo ]   # due to patch
-      ++ optionals selinuxSupport [ libselinux libsepol ];
-
-    crossAttrs = {
-      buildInputs = [ gmp.crossDrv ]
-        ++ optional aclSupport acl.crossDrv
-        ++ optional attrSupport attr.crossDrv
-        ++ optionals selinuxSupport [ libselinux.crossDrv libsepol.crossDrv ]
-        ++ optional (stdenv.ccCross.libc ? libiconv)
-          stdenv.ccCross.libc.libiconv.crossDrv;
-
-      # Prevents attempts of running 'help2man' on cross-built binaries.
-      PERL = "missing";
-
-      # Works around a bug with 8.26:
-      # Makefile:3440: *** Recursive variable 'INSTALL' references itself (eventually).  Stop.
-      preInstall = ''
-        sed -i Makefile -e 's|^INSTALL =.*|INSTALL = ${self}/bin/install -c|'
-      '';
-
-      postInstall = ''
-        rm $out/share/man/man1/*
-        cp ${self}/share/man/man1/* $out/share/man/man1
-      '';
-
-      # Needed for fstatfs()
-      # I don't know why it is not properly detected cross building with glibc.
-      configureFlags = [ "fu_cv_sys_stat_statfs2_bsize=yes" ];
-      doCheck = false;
-    };
-
-    # The tests are known broken on Cygwin
-    # (http://thread.gmane.org/gmane.comp.gnu.core-utils.bugs/19025),
-    # Darwin (http://thread.gmane.org/gmane.comp.gnu.core-utils.bugs/19351),
-    # and {Open,Free}BSD.
-    # With non-standard storeDir: https://github.com/NixOS/nix/issues/512
-    doCheck = stdenv ? glibc && builtins.storeDir == "/nix/store";
-
-    # Saw random failures like ‘help2man: can't get '--help' info from
-    # man/sha512sum.td/sha512sum’.
-    enableParallelBuilding = false;
-
-    NIX_LDFLAGS = optionalString selinuxSupport "-lsepol";
-    FORCE_UNSAFE_CONFIGURE = optionalString stdenv.isSunOS "1";
-
-    makeFlags = optionalString stdenv.isDarwin "CFLAGS=-D_FORTIFY_SOURCE=0";
-
-    meta = {
-      homepage = http://www.gnu.org/software/coreutils/;
-      description = "The basic file, shell and text manipulation utilities of the GNU operating system";
-
-      longDescription = ''
-        The GNU Core Utilities are the basic file, shell and text
-        manipulation utilities of the GNU operating system.  These are
-        the core utilities which are expected to exist on every
-        operating system.
-      '';
-
-      license = licenses.gpl3Plus;
-
-      platforms = platforms.all;
-
-      maintainers = [ maintainers.eelco ];
-    };
   };
-in
+
-  self
+  # The tests are known broken on Cygwin
+  # (http://thread.gmane.org/gmane.comp.gnu.core-utils.bugs/19025),
+  # Darwin (http://thread.gmane.org/gmane.comp.gnu.core-utils.bugs/19351),
+  # and {Open,Free}BSD.
+  # With non-standard storeDir: https://github.com/NixOS/nix/issues/512
+  doCheck = stdenv ? glibc && builtins.storeDir == "/nix/store";
+
+  # Saw random failures like ‘help2man: can't get '--help' info from
+  # man/sha512sum.td/sha512sum’.
+  enableParallelBuilding = false;
+
+  NIX_LDFLAGS = optionalString selinuxSupport "-lsepol";
+  FORCE_UNSAFE_CONFIGURE = optionalString stdenv.isSunOS "1";
+
+  makeFlags = optionalString stdenv.isDarwin "CFLAGS=-D_FORTIFY_SOURCE=0";
+
+  meta = {
+    homepage = http://www.gnu.org/software/coreutils/;
+    description = "The basic file, shell and text manipulation utilities of the GNU operating system";
+
+    longDescription = ''
+      The GNU Core Utilities are the basic file, shell and text
+      manipulation utilities of the GNU operating system.  These are
+      the core utilities which are expected to exist on every
+      operating system.
+    '';
+
+    license = licenses.gpl3Plus;
+
+    platforms = platforms.all;
+
+    maintainers = [ maintainers.eelco ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -10,26 +10,12 @@ self: pkgs:
 
 with pkgs;
 
-let
-  defaultScope = pkgs // pkgs.xorg;
-in
-
 {
 
   # Allow callPackage to fill in the pkgs argument
   inherit pkgs;
 
 
-  # We use `callPackage' to be able to omit function arguments that
-  # can be obtained from `pkgs' or `pkgs.xorg' (i.e. `defaultScope').
-  # Use `newScope' for sets of packages in `pkgs' (see e.g. `gnome'
-  # below).
-  callPackage = newScope {};
-
-  callPackages = lib.callPackagesWith defaultScope;
-
-  newScope = extra: lib.callPackageWith (defaultScope // extra);
-
   # Override system. This is useful to build i686 packages on x86_64-linux.
   forceSystem = system: kernel: nixpkgsFun {
     inherit system;
@@ -39,15 +25,9 @@ in
   # Used by wine, firefox with debugging version of Flash, ...
   pkgsi686Linux = forceSystem "i686-linux" "i386";
 
-  callPackage_i686 = lib.callPackageWith (pkgsi686Linux // pkgsi686Linux.xorg);
+  callPackage_i686 = pkgsi686Linux.callPackage;
 
-  forceNativeDrv = drv:
+  forcedNativePackages = if hostPlatform == buildPlatform then pkgs else buildPackages;
-    # Even when cross compiling, some packages come from the stdenv's
-    # bootstrapping package set. Those packages are only built for the native
-    # platform.
-    if crossSystem != null && drv ? crossDrv
-    then drv // { crossDrv = drv.nativeDrv; }
-    else drv;
 
   # A stdenv capable of building 32-bit binaries.  On x86_64-linux,
   # it uses GCC compiled with multilib support; on i686-linux, it's
@@ -3274,7 +3254,7 @@ in
   pngout = callPackage ../tools/graphics/pngout { };
 
   hurdPartedCross =
-    if crossSystem != null && crossSystem.config == "i586-pc-gnu"
+    if targetPlatform != buildPlatform && targetPlatform.config == "i586-pc-gnu"
     then (makeOverridable
             ({ hurd }:
               (parted.override {
@@ -4779,44 +4759,48 @@ in
 
   gccApple = throw "gccApple is no longer supported";
 
-  gccCrossStageStatic = let
+  gccCrossStageStatic = assert targetPlatform != buildPlatform; let
     libcCross1 =
       if stdenv.cross.libc == "msvcrt" then windows.mingw_w64_headers
       else if stdenv.cross.libc == "libSystem" then darwin.xcode
       else null;
     in wrapGCCCross {
-      gcc = forceNativeDrv (gcc.cc.override {
+      gcc = forcedNativePackages.gcc.cc.override {
-        cross = crossSystem;
+        cross = targetPlatform;
         crossStageStatic = true;
         langCC = false;
         libcCross = libcCross1;
         enableShared = false;
-      });
+        # Why is this needed?
+        inherit (forcedNativePackages) binutilsCross;
+      };
       libc = libcCross1;
       binutils = binutilsCross;
-      cross = crossSystem;
+      cross = targetPlatform;
   };
 
   # Only needed for mingw builds
-  gccCrossMingw2 = wrapGCCCross {
+  gccCrossMingw2 = assert targetPlatform != buildPlatform; wrapGCCCross {
     gcc = gccCrossStageStatic.gcc;
     libc = windows.mingw_headers2;
     binutils = binutilsCross;
-    cross = assert crossSystem != null; crossSystem;
+    cross = targetPlatform;
   };
 
-  gccCrossStageFinal = wrapGCCCross {
+  gccCrossStageFinal = assert targetPlatform != buildPlatform; wrapGCCCross {
-    gcc = forceNativeDrv (gcc.cc.override {
+    gcc = forcedNativePackages.gcc.cc.override {
-      cross = crossSystem;
+      cross = targetPlatform;
       crossStageStatic = false;
 
       # XXX: We have troubles cross-compiling libstdc++ on MinGW (see
       # <http://hydra.nixos.org/build/4268232>), so don't even try.
-      langCC = crossSystem.config != "i686-pc-mingw32";
+      langCC = targetPlatform.config != "i686-pc-mingw32";
-    });
+      # Why is this needed?
+      inherit (forcedNativePackages) binutilsCross;
+    };
     libc = libcCross;
     binutils = binutilsCross;
-    cross = crossSystem;
+    cross = targetPlatform;
   };
 
   gcc45 = lowPrio (wrapCC (callPackage ../development/compilers/gcc/4.5 {
@@ -4834,7 +4818,7 @@ in
     # and host != build), `cross' must be null but the cross-libc must still
     # be passed.
     cross = null;
-    libcCross = if crossSystem != null then libcCross else null;
+    libcCross = if targetPlatform != buildPlatform then libcCross else null;
   }));
 
   gcc48 = lowPrio (wrapCC (callPackage ../development/compilers/gcc/4.8 {
@@ -4847,7 +4831,7 @@ in
     # and host != build), `cross' must be null but the cross-libc must still
     # be passed.
     cross = null;
-    libcCross = if crossSystem != null then libcCross else null;
+    libcCross = if targetPlatform != buildPlatform then libcCross else null;
 
     isl = if !stdenv.isDarwin then isl_0_14 else null;
     cloog = if !stdenv.isDarwin then cloog else null;
@@ -4864,7 +4848,7 @@ in
     # and host != build), `cross' must be null but the cross-libc must still
     # be passed.
     cross = null;
-    libcCross = if crossSystem != null then libcCross else null;
+    libcCross = if targetPlatform != buildPlatform then libcCross else null;
 
     isl = if !stdenv.isDarwin then isl_0_11 else null;
 
@@ -4881,7 +4865,7 @@ in
     # and host != build), `cross' must be null but the cross-libc must still
     # be passed.
     cross = null;
-    libcCross = if crossSystem != null then libcCross else null;
+    libcCross = if targetPlatform != buildPlatform then libcCross else null;
 
     isl = if !stdenv.isDarwin then isl_0_14 else null;
   }));
@@ -4896,7 +4880,7 @@ in
     # and host != build), `cross' must be null but the cross-libc must still
     # be passed.
     cross = null;
-    libcCross = if crossSystem != null then libcCross else null;
+    libcCross = if targetPlatform != buildPlatform then libcCross else null;
 
     isl = if !stdenv.isDarwin then isl_0_14 else null;
   }));
@@ -5029,7 +5013,7 @@ in
 
   # Haskell and GHC
 
-  haskell = callPackage ./haskell-packages.nix { inherit crossSystem; };
+  haskell = callPackage ./haskell-packages.nix { };
 
   haskellPackages = haskell.packages.ghc801.override {
     overrides = config.haskellPackageOverrides or (self: super: {});
@@ -5507,12 +5491,12 @@ in
   wrapGCCCross =
     {gcc, libc, binutils, cross, shell ? "", name ? "gcc-cross-wrapper"}:
 
-    forceNativeDrv (callPackage ../build-support/gcc-cross-wrapper {
+    forcedNativePackages.callPackage ../build-support/gcc-cross-wrapper {
       nativeTools = false;
       nativeLibc = false;
       noLibc = (libc == null);
       inherit gcc binutils libc shell name cross;
-    });
+    };
 
   # prolog
   yap = callPackage ../development/compilers/yap { };
@@ -6092,12 +6076,12 @@ in
     gold = false;
   });
 
-  binutilsCross = assert crossSystem != null; lowPrio (forceNativeDrv (
+  binutilsCross = assert targetPlatform != buildPlatform; lowPrio (
-    if crossSystem.libc == "libSystem" then darwin.cctools_cross
+    if targetPlatform.libc == "libSystem" then darwin.cctools_cross
-    else binutils.override {
+    else forcedNativePackages.binutils.override {
       noSysDirs = true;
-      cross = crossSystem;
+      cross = targetPlatform;
-    }));
+    });
 
   bison2 = callPackage ../development/tools/parsing/bison/2.x.nix { };
   bison3 = callPackage ../development/tools/parsing/bison/3.x.nix { };
@@ -6566,9 +6550,9 @@ in
      cross_renaming: we should make all programs use pkgconfig as
      nativeBuildInput after the renaming.
      */
-  pkgconfig = forceNativeDrv (callPackage ../development/tools/misc/pkgconfig {
+  pkgconfig = forcedNativePackages.callPackage ../development/tools/misc/pkgconfig {
     fetchurl = fetchurlBoot;
-  });
+  };
   pkgconfigUpstream = lowPrio (pkgconfig.override { vanilla = true; });
 
   postiats-utilities = callPackage ../development/tools/postiats-utilities {};
@@ -6742,7 +6726,7 @@ in
   gdbGuile = lowPrio (gdb.override { inherit guile; });
 
   gdbCross = lowPrio (callPackage ../development/tools/misc/gdb {
-    target = crossSystem;
+    target = if targetPlatform != buildPlatform then targetPlatform else null;
   });
 
   gdb-multitarget = lowPrio (gdb.override { multitarget = true; });
@@ -7344,10 +7328,10 @@ in
     withGd = true;
   };
 
-  glibcCross = forceNativeDrv (glibc.override {
+  glibcCross = forcedNativePackages.glibc.override {
     gccCross = gccCrossStageStatic;
     linuxHeaders = linuxHeadersCross;
-  });
+  };
 
   # We can choose:
   libcCrossChooser = name: if name == "glibc" then glibcCross
@@ -7356,7 +7340,7 @@ in
     else if name == "libSystem" then darwin.xcode
     else throw "Unknown libc";
 
-  libcCross = assert crossSystem != null; libcCrossChooser crossSystem.libc;
+  libcCross = assert targetPlatform != buildPlatform; libcCrossChooser targetPlatform.libc;
 
   # Only supported on Linux
   glibcLocales = if stdenv.isLinux then callPackage ../development/libraries/glibc/locales.nix { } else null;
@@ -8265,9 +8249,9 @@ in
   # glibc provides libiconv so systems with glibc don't need to build libiconv
   # separately, but we also provide libiconvReal, which will always be a
   # standalone libiconv, just in case you want it
-  libiconv = if crossSystem != null then
+  libiconv = if stdenv ? cross then
-    (if crossSystem.libc == "glibc" then libcCross
+    (if stdenv.cross.libc == "glibc" then libcCross
-      else if crossSystem.libc == "libSystem" then darwin.libiconv
+      else if stdenv.cross.libc == "libSystem" then darwin.libiconv
       else libiconvReal)
     else if stdenv.isGlibc then glibcIconv stdenv.cc.libc
     else if stdenv.isDarwin then darwin.libiconv
@@ -10918,8 +10902,8 @@ in
     cmdline = callPackage ../os-specific/darwin/command-line-tools {};
     apple-source-releases = callPackage ../os-specific/darwin/apple-source-releases { };
   in apple-source-releases // rec {
-    cctools_cross = callPackage (forceNativeDrv (callPackage ../os-specific/darwin/cctools/port.nix {}).cross) {
+    cctools_cross = callPackage (forcedNativePackages.callPackage ../os-specific/darwin/cctools/port.nix {}).cross {
-      cross = assert crossSystem != null; crossSystem;
+      cross = assert targetPlatform != buildPlatform; targetPlatform;
       inherit maloader;
       xctoolchain = xcode.toolchain;
     };
@@ -10992,7 +10976,7 @@ in
   libossp_uuid = callPackage ../development/libraries/libossp-uuid { };
 
   libuuid =
-    if crossSystem != null && crossSystem.config == "i586-pc-gnu"
+    if targetPlatform != buildPlatform && targetPlatform.config == "i586-pc-gnu"
     then (utillinuxMinimal // {
       crossDrv = lib.overrideDerivation utillinuxMinimal.crossDrv (args: {
         # `libblkid' fails to build on GNU/Hurd.
@@ -11077,7 +11061,7 @@ in
 
   # GNU/Hurd core packages.
   gnu = recurseIntoAttrs (callPackage ../os-specific/gnu {
-    inherit platform crossSystem;
+    inherit platform;
   });
 
   hwdata = callPackage ../os-specific/linux/hwdata { };
@@ -11156,13 +11140,13 @@ in
 
   linuxHeaders = linuxHeaders_4_4;
 
-  linuxHeaders24Cross = forceNativeDrv (callPackage ../os-specific/linux/kernel-headers/2.4.nix {
+  linuxHeaders24Cross = forcedNativePackages.callPackage ../os-specific/linux/kernel-headers/2.4.nix {
-    cross = assert crossSystem != null; crossSystem;
+    cross = assert targetPlatform != buildPlatform; targetPlatform;
-  });
+  };
 
-  linuxHeaders26Cross = forceNativeDrv (callPackage ../os-specific/linux/kernel-headers/4.4.nix {
+  linuxHeaders26Cross = forcedNativePackages.callPackage ../os-specific/linux/kernel-headers/4.4.nix {
-    cross = assert crossSystem != null; crossSystem;
+    cross = assert targetPlatform != buildPlatform; targetPlatform;
-  });
+  };
 
   linuxHeaders_3_18 = callPackage ../os-specific/linux/kernel-headers/3.18.nix { };
 
@@ -11173,8 +11157,8 @@ in
     else if ver == "2.6" then linuxHeaders26Cross
     else throw "Unknown linux kernel version";
 
-  linuxHeadersCross = assert crossSystem != null;
+  linuxHeadersCross = assert targetPlatform != buildPlatform;
-    linuxHeadersCrossChooser crossSystem.platform.kernelMajor;
+    linuxHeadersCrossChooser targetPlatform.platform.kernelMajor;
 
   kernelPatches = callPackage ../os-specific/linux/kernel/patches.nix { };
 
@@ -11839,7 +11823,7 @@ in
   uclibcCross = lowPrio (callPackage ../os-specific/linux/uclibc {
     linuxHeaders = linuxHeadersCross;
     gccCross = gccCrossStageStatic;
-    cross = assert crossSystem != null; crossSystem;
+    cross = assert targetPlatform != buildPlatform; targetPlatform;
   });
 
   udev = systemd;

pkgs/top-level/default.nix

@@ -83,7 +83,24 @@ in let
   boot = import ../stdenv/booter.nix { inherit lib allPackages; };
 
   stages = stdenvStages {
-    inherit lib system platform crossSystem config overlays;
+    # One would think that `localSystem` and `crossSystem` overlap horribly with
+    # the three `*Platforms` (`buildPlatform`, `hostPlatform,` and
+    # `targetPlatform`; see `stage.nix` or the manual). Actually, those
+    # identifiers I, @Ericson2314, purposefully not used here to draw a subtle
+    # but important distinction:
+    #
+    # While the granularity of having 3 platforms is necessary to properly
+    # *build* packages, it is overkill for specifying the user's *intent* when
+    # making a build plan or package set. A simple "build vs deploy" dichotomy
+    # is adequate: the "sliding window" principle described in the manual shows
+    # how to interpolate between the these two "end points" to get the 3
+    # platform triple for each bootstrapping stage.
+    #
+    # Also, less philosophically but quite practically, `crossSystem` should be
+    # null when one doesn't want to cross-compile, while the `*Platform`s are
+    # always non-null. `localSystem` is always non-null.
+    localSystem = { inherit system platform; };
+    inherit lib crossSystem config overlays;
   };
 
   pkgs = boot stages;

pkgs/top-level/haskell-packages.nix

@@ -1,4 +1,4 @@
-{ pkgs, callPackage, stdenv, crossSystem }:
+{ pkgs, callPackage, stdenv, buildPlatform, targetPlatform }:
 
 rec {
 
@@ -55,7 +55,7 @@ rec {
     ghcHEAD = callPackage ../development/compilers/ghc/head.nix rec {
       bootPkgs = packages.ghc7103;
       inherit (bootPkgs) alex happy;
-      inherit crossSystem;
+      inherit buildPlatform targetPlatform;
       selfPkgs = packages.ghcHEAD;
     };
     ghcjs = packages.ghc7103.callPackage ../development/compilers/ghcjs {

pkgs/top-level/release-cross.nix

@@ -32,8 +32,10 @@ let
 in
 
 {
-  # These `nativeDrv`s should be identical to their vanilla ones --- cross
+  # These derivations from a cross package set's `buildPackages` should be
-  # compiling should not affect the native derivation.
+  # identical to their vanilla equivalents --- none of these package should
+  # observe the target platform which is the only difference between those
+  # package sets.
   ensureUnaffected = let
     # Absurd values are fine here, as we are not building anything. In fact,
     # there probably a good idea to try to be "more parametric" --- i.e. avoid
@@ -47,8 +49,12 @@ in
     # good idea lest there be some irrelevant pass-through debug attrs that
     # cause false negatives.
     testEqualOne = path: system: let
-      f = attrs: builtins.toString (lib.getAttrFromPath path (allPackages attrs));
+      f = path: attrs: builtins.toString (lib.getAttrFromPath path (allPackages attrs));
-    in assert f { inherit system; } == f { inherit system crossSystem; }; true;
+    in assert
+        f path { inherit system; }
+        ==
+        f (["buildPackages"] ++ path) { inherit system crossSystem; };
+      true;
 
     testEqual = path: systems: forAllSupportedSystems systems (testEqualOne path);
 

pkgs/top-level/release-lib.nix

@@ -76,8 +76,9 @@ rec {
    * parameter for allPackages, defining the target platform for cross builds,
    * and triggering the build of the host derivation (cross built - crossDrv). */
   mapTestOnCross = crossSystem: mapAttrsRecursive
-    (path: systems: testOnCross crossSystem systems
+    (path: systems: testOnCross crossSystem systems (pkgs: addMetaAttrs
-      (pkgs: addMetaAttrs { maintainers = crossMaintainers; } (getAttrFromPath path pkgs)));
+      { maintainers = crossMaintainers; }
+      (getAttrFromPath path pkgs.splicedPackages)));
 
 
   /* Recursively map a (nested) set of derivations to an isomorphic

pkgs/top-level/splice.nix

@@ -0,0 +1,83 @@
+# The `splicedPackages' package set, and its use by `callPackage`
+#
+# The `buildPackages` pkg set is a new concept, and the vast majority package
+# expression (the other *.nix files) are not designed with it in mind. This
+# presents us with a problem with how to get the right version (build-time vs
+# run-time) of a package to a consumer that isn't used to thinking so cleverly.
+#
+# The solution is to splice the package sets together as we do below, so every
+# `callPackage`d expression in fact gets both versions. Each# derivation (and
+# each derivation's outputs) consists of the run-time version, augmented with a
+# `nativeDrv` field for the build-time version, and `crossDrv` field for the
+# run-time version.
+#
+# We could have used any names we want for the disambiguated versions, but
+# `crossDrv` and `nativeDrv` were somewhat similarly used for the old
+# cross-compiling infrastructure. The names are mostly invisible as
+# `mkDerivation` knows how to pull out the right ones for `buildDepends` and
+# friends, but a few packages use them directly, so it seemed efficient (to
+# @Ericson2314) to reuse those names, at least initially, to minimize breakage.
+#
+# For performance reasons, rather than uniformally splice in all cases, we only
+# do so when `pkgs` and `buildPackages` are distinct. The `actuallySplice`
+# parameter there the boolean value of that equality check.
+lib: pkgs: actuallySplice:
+
+let
+  defaultBuildScope = pkgs.buildPackages // pkgs.buildPackages.xorg;
+  # TODO(@Ericson2314): we shouldn't preclude run-time fetching by removing
+  # these attributes. We should have a more general solution for selecting
+  # whether `nativeDrv` or `crossDrv` is the default in `defaultScope`.
+  pkgsWithoutFetchers = lib.filterAttrs (n: _: !lib.hasPrefix "fetch" n) pkgs;
+  defaultRunScope = pkgsWithoutFetchers // pkgs.xorg;
+
+  splicer = buildPkgs: runPkgs: let
+    mash = buildPkgs // runPkgs;
+    merge = name: {
+      inherit name;
+      value = let
+        defaultValue = mash.${name};
+        buildValue = buildPkgs.${name} or {};
+        runValue = runPkgs.${name} or {};
+        augmentedValue = defaultValue
+          // (lib.optionalAttrs (buildPkgs ? ${name}) { nativeDrv = buildValue; })
+          // (lib.optionalAttrs (runPkgs ? ${name}) { crossDrv = runValue; });
+        # Get the set of outputs of a derivation
+        getOutputs = value:
+          lib.genAttrs (value.outputs or []) (output: value.${output});
+      in
+        # Certain *Cross derivations will fail assertions, but we need their
+        # nativeDrv. We are assuming anything that fails to evaluate is an
+        # attrset (including derivation) and thus can be unioned.
+        if !(builtins.tryEval defaultValue).success then augmentedValue
+        # The derivation along with its outputs, which we recur
+        # on to splice them together.
+        else if lib.isDerivation defaultValue then augmentedValue
+          // splicer (getOutputs buildValue) (getOutputs runValue)
+        # Just recur on plain attrsets
+        else if lib.isAttrs defaultValue then splicer buildValue runValue
+        # Don't be fancy about non-derivations. But we could have used used
+        # `__functor__` for functions instead.
+        else defaultValue;
+    };
+  in lib.listToAttrs (map merge (lib.attrNames mash));
+
+  splicedPackages =
+    if actuallySplice
+    then splicer defaultBuildScope defaultRunScope
+    else pkgs // pkgs.xorg;
+
+in
+
+{
+  splicedPackages = splicedPackages // { recurseForDerivations = false; };
+
+  # We use `callPackage' to be able to omit function arguments that can be
+  # obtained `pkgs` or `buildPackages` and their `xorg` package sets. Use
+  # `newScope' for sets of packages in `pkgs' (see e.g. `gnome' below).
+  callPackage = pkgs.newScope {};
+
+  callPackages = lib.callPackagesWith splicedPackages;
+
+  newScope = extra: lib.callPackageWith (splicedPackages // extra);
+}

pkgs/top-level/stage.nix

@@ -9,8 +9,45 @@
    import `pkgs/default.nix` or `default.nix`. */
 
 
-{ # The system (e.g., `i686-linux') for which to build the packages.
+{ ## Misc parameters kept the same for all stages
-  system
+  ##
+
+  # Utility functions, could just import but passing in for efficiency
+  lib
+
+, # Use to reevaluate Nixpkgs; a dirty hack that should be removed
+  nixpkgsFun
+
+  ## Platform parameters
+  ##
+  ## The "build" "host" "target" terminology below comes from GNU Autotools. See
+  ## its documentation for more information on what those words mean. Note that
+  ## each should always be defined, even when not cross compiling.
+  ##
+  ## For purposes of bootstrapping, think of each stage as a "sliding window"
+  ## over a list of platforms. Specifically, the host platform of the previous
+  ## stage becomes the build platform of the current one, and likewise the
+  ## target platform of the previous stage becomes the host platform of the
+  ## current one.
+  ##
+
+, # The platform on which packages are built. Consists of `system`, a
+  # string (e.g.,`i686-linux') identifying the most import attributes of the
+  # build platform, and `platform` a set of other details.
+  buildPlatform
+
+, # The platform on which packages run.
+  hostPlatform
+
+, # The platform which build tools (especially compilers) build for in this stage,
+  targetPlatform
+
+  ## Other parameters
+  ##
+
+, # The package set used at build-time. If null, `buildPackages` will
+  # be defined internally as the produced package set as itself.
+  buildPackages
 
 , # The standard environment to use for building packages.
   stdenv
@@ -21,21 +58,19 @@
   allowCustomOverrides
 
 , # Non-GNU/Linux OSes are currently "impure" platforms, with their libc
-  # outside of the store.  Thus, GCC, GFortran, & co. must always look for
+  # outside of the store.  Thus, GCC, GFortran, & co. must always look for files
-  # files in standard system directories (/usr/include, etc.)
+  # in standard system directories (/usr/include, etc.)
-  noSysDirs ? (system != "x86_64-freebsd" && system != "i686-freebsd"
+  noSysDirs ? buildPlatform.system != "x86_64-freebsd"
-               && system != "x86_64-solaris"
+           && buildPlatform.system != "i686-freebsd"
-               && system != "x86_64-kfreebsd-gnu")
+           && buildPlatform.system != "x86_64-solaris"
+           && buildPlatform.system != "x86_64-kfreebsd-gnu"
 
 , # The configuration attribute set
   config
 
-, overlays # List of overlays to use in the fix-point.
+, # A list of overlays (Additional `self: super: { .. }` customization
-
+  # functions) to be fixed together in the produced package set
-, crossSystem
+  overlays
-, platform
-, lib
-, nixpkgsFun
 }:
 
 let
@@ -50,11 +85,28 @@ let
     };
 
   stdenvBootstappingAndPlatforms = self: super: {
-    stdenv = stdenv // { inherit platform; };
+    buildPackages = (if buildPackages == null then self else buildPackages)
-    inherit
+      // { recurseForDerivations = false; };
-      system platform crossSystem;
+    inherit stdenv
+      buildPlatform hostPlatform targetPlatform;
   };
 
+  # The old identifiers for cross-compiling. These should eventually be removed,
+  # and the packages that rely on them refactored accordingly.
+  platformCompat = self: super: let
+    # TODO(@Ericson2314) this causes infinite recursion
+    #inherit (self) buildPlatform hostPlatform targetPlatform;
+  in {
+    stdenv = super.stdenv // {
+      inherit (buildPlatform) platform;
+    } // lib.optionalAttrs (targetPlatform != buildPlatform) {
+      cross = targetPlatform;
+    };
+    inherit (buildPlatform) system platform;
+  };
+
+  splice = self: super: import ./splice.nix lib self (buildPackages != null);
+
   allPackages = self: super:
     let res = import ./all-packages.nix
       { inherit lib nixpkgsFun noSysDirs config; }
@@ -83,8 +135,10 @@ let
   # The complete chain of package set builders, applied from top to bottom
   toFix = lib.foldl' (lib.flip lib.extends) (self: {}) ([
     stdenvBootstappingAndPlatforms
+    platformCompat
     stdenvAdapters
     trivialBuilders
+    splice
     allPackages
     aliases
     stdenvOverrides