Merge #33057: stdenv meta checks: make them lazy

Closes #22277 - it's superseded;  I have some WIP on evaluation
performance, but best do that in a separate PR/thread.

lib/customisation.nix

@@ -36,7 +36,7 @@ rec {
   overrideDerivation = drv: f:
     let
       newDrv = derivation (drv.drvAttrs // (f drv));
-    in addPassthru newDrv (
+    in lib.flip (extendDerivation true) newDrv (
       { meta = drv.meta or {};
         passthru = if drv ? passthru then drv.passthru else {};
       }
@@ -131,8 +131,8 @@ rec {
 
 
   /* Add attributes to each output of a derivation without changing
-     the derivation itself. */
-  addPassthru = drv: passthru:
+     the derivation itself and check a given condition when evaluating. */
+  extendDerivation = condition: passthru: drv:
     let
       outputs = drv.outputs or [ "out" ];
 
@@ -142,13 +142,23 @@ rec {
       outputToAttrListElement = outputName:
         { name = outputName;
           value = commonAttrs // {
-            inherit (drv.${outputName}) outPath drvPath type outputName;
+            inherit (drv.${outputName}) type outputName;
+            drvPath = assert condition; drv.${outputName}.drvPath;
+            outPath = assert condition; drv.${outputName}.outPath;
           };
         };
 
       outputsList = map outputToAttrListElement outputs;
-  in commonAttrs // { outputUnspecified = true; };
+    in commonAttrs // {
+      outputUnspecified = true;
+      drvPath = assert condition; drv.drvPath;
+      outPath = assert condition; drv.outPath;
+    };
 
+  /* Add attributes to each output of a derivation without changing
+     the derivation itself. */
+  addPassthru = lib.warn "`addPassthru` is deprecated, replace with `extendDerivation true`"
+                         (extendDerivation true);
 
   /* Strip a derivation of all non-essential attributes, returning
      only those needed by hydra-eval-jobs. Also strictly evaluate the

lib/default.nix

@@ -87,7 +87,8 @@ let
     inherit (stringsWithDeps) textClosureList textClosureMap
       noDepEntry fullDepEntry packEntry stringAfter;
     inherit (customisation) overrideDerivation makeOverridable
-      callPackageWith callPackagesWith addPassthru hydraJob makeScope;
+      callPackageWith callPackagesWith extendDerivation addPassthru
+      hydraJob makeScope;
     inherit (meta) addMetaAttrs dontDistribute setName updateName
       appendToName mapDerivationAttrset lowPrio lowPrioSet hiPrio
       hiPrioSet;