diff --git a/pkgs/development/compilers/rust/patches/net-tcp-disable-tests.patch b/pkgs/development/compilers/rust/patches/net-tcp-disable-tests.patch
deleted file mode 100644
index 583a6027f83..00000000000
--- a/pkgs/development/compilers/rust/patches/net-tcp-disable-tests.patch
+++ /dev/null
@@ -1,92 +0,0 @@
-diff -ru rustc-1.36.0-src-orig/src/libstd/net/tcp.rs rustc-1.36.0-src/src/libstd/net/tcp.rs
---- rustc-1.36.0-src-orig/src/libstd/net/tcp.rs	2019-07-03 10:00:00.000000000 +0200
-+++ rustc-1.36.0-src/src/libstd/net/tcp.rs	2019-07-07 11:33:35.378130207 +0200
-@@ -973,6 +973,7 @@
-         }
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     fn listen_localhost() {
-         let socket_addr = next_test_ip4();
-@@ -1031,6 +1032,7 @@
-         })
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     fn read_eof() {
-         each_ip(&mut |addr| {
-@@ -1050,6 +1052,7 @@
-         })
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     fn write_close() {
-         each_ip(&mut |addr| {
-@@ -1076,6 +1079,7 @@
-         })
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     fn multiple_connect_serial() {
-         each_ip(&mut |addr| {
-@@ -1098,6 +1102,7 @@
-         })
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     fn multiple_connect_interleaved_greedy_schedule() {
-         const MAX: usize = 10;
-@@ -1134,6 +1139,7 @@
-     }
- 
-     #[test]
-+    #[cfg_attr(target_os = "macos", ignore)]
-     fn multiple_connect_interleaved_lazy_schedule() {
-         const MAX: usize = 10;
-         each_ip(&mut |addr| {
-@@ -1467,6 +1473,7 @@
-     }
- 
-     #[test]
-+    #[cfg_attr(target_os = "macos", ignore)]
-     fn clone_while_reading() {
-         each_ip(&mut |addr| {
-             let accept = t!(TcpListener::bind(&addr));
-@@ -1597,7 +1604,7 @@
- 
-     // FIXME: re-enabled openbsd tests once their socket timeout code
-     //        no longer has rounding errors.
--    #[cfg_attr(any(target_os = "netbsd", target_os = "openbsd"), ignore)]
-+    #[cfg_attr(any(target_os = "netbsd", target_os = "openbsd", target_os = "macos"), ignore)]
-     #[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
-     #[test]
-     fn timeouts() {
-@@ -1643,6 +1650,7 @@
-         drop(listener);
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     #[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
-     fn test_read_with_timeout() {
-@@ -1687,6 +1695,7 @@
-         drop(listener);
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     #[cfg_attr(target_env = "sgx", ignore)]
-     fn nodelay() {
-@@ -1719,6 +1728,7 @@
-         assert_eq!(ttl, t!(stream.ttl()));
-     }
- 
-+    #[cfg_attr(target_os = "macos", ignore)]
-     #[test]
-     #[cfg_attr(target_env = "sgx", ignore)]
-     fn set_nonblocking() {
diff --git a/pkgs/development/compilers/rust/patches/stdsimd-disable-doctest.patch b/pkgs/development/compilers/rust/patches/stdsimd-disable-doctest.patch
deleted file mode 100644
index 6ef7fd0f7ce..00000000000
--- a/pkgs/development/compilers/rust/patches/stdsimd-disable-doctest.patch
+++ /dev/null
@@ -1,20 +0,0 @@
-diff --git a/src/stdsimd/coresimd/x86/mod.rs b/src/stdsimd/coresimd/x86/mod.rs
-index 32915c332..7cb54f31e 100644
---- a/src/stdsimd/coresimd/x86/mod.rs
-+++ b/src/stdsimd/coresimd/x86/mod.rs
-@@ -279,7 +279,6 @@ types! {
-     ///
-     /// # Examples
-     ///
--    /// ```
-     /// # #![feature(cfg_target_feature, target_feature, stdsimd)]
-     /// # #![cfg_attr(not(dox), no_std)]
-     /// # #[cfg(not(dox))]
-@@ -301,7 +300,6 @@ types! {
-     /// # }
-     /// # if is_x86_feature_detected!("sse") { unsafe { foo() } }
-     /// # }
--    /// ```
-     pub struct __m256(f32, f32, f32, f32, f32, f32, f32, f32);
- 
-     /// 256-bit wide set of four `f64` types, x86-specific
diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index 433dc1719fb..27336aa501b 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -1,8 +1,8 @@
 { stdenv, removeReferencesTo, pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget
-, fetchurl, file, python2, tzdata, ps
+, fetchurl, file, python2
 , llvm_7, darwin, git, cmake, rustPlatform
 , pkgconfig, openssl
-, which, libffi, gdb
+, which, libffi
 , withBundledLLVM ? false
 }:
 
@@ -98,18 +98,6 @@ in stdenv.mkDerivation rec {
       --replace 'BOOTSTRAP_ARGS :=' 'BOOTSTRAP_ARGS := --jobs $(NIX_BUILD_CORES)'
   '';
 
-  patches = [
-    ./patches/net-tcp-disable-tests.patch
-
-    # Re-evaluate if this we need to disable this one
-    #./patches/stdsimd-disable-doctest.patch
-
-    # Fails on hydra - not locally; the exact reason is unknown.
-    # Comments in the test suggest that some non-reproducible environment
-    # variables such $RANDOM can make it fail.
-    # ./patches/disable-test-inherit-env.patch
-  ];
-
   # the rust build system complains that nix alters the checksums
   dontFixLibtool = true;
 
@@ -122,45 +110,18 @@ in stdenv.mkDerivation rec {
     sed -i configure \
       -e '/probe_need CFG_CURL curl/d'
 
-    # On Hydra: `TcpListener::bind(&addr)`: Address already in use (os error 98)'
-    sed '/^ *fn fast_rebind()/i#[ignore]' -i src/libstd/net/tcp.rs
-
-    # https://github.com/rust-lang/rust/issues/39522
-    echo removing gdb-version-sensitive tests...
-    find src/test/debuginfo -type f -execdir grep -q ignore-gdb-version '{}' \; -print -delete
-    rm src/test/debuginfo/{borrowed-c-style-enum.rs,c-style-enum-in-composite.rs,gdb-pretty-struct-and-enums.rs,generic-enum-with-different-disr-sizes.rs}
-
     # Useful debugging parameter
     # export VERBOSE=1
-  '' + optionalString stdenv.isDarwin ''
-    # Disable all lldb tests.
-    # error: Can't run LLDB test because LLDB's python path is not set
-    rm -vr src/test/debuginfo/*
-    rm -v src/test/run-pass/backtrace-debuginfo.rs || true
-
-    # error: No such file or directory
-    rm -v src/test/ui/run-pass/issues/issue-45731.rs || true
-
-    # Disable tests that fail when sandboxing is enabled.
-    substituteInPlace src/libstd/sys/unix/ext/net.rs \
-        --replace '#[test]' '#[test] #[ignore]'
-    substituteInPlace src/test/run-pass/env-home-dir.rs \
-        --replace 'home_dir().is_some()' true
-    rm -v src/test/run-pass/fds-are-cloexec.rs || true  # FIXME: pipes?
-    rm -v src/test/ui/run-pass/threads-sendsync/sync-send-in-std.rs || true  # FIXME: ???
   '';
 
   # rustc unfortunately needs cmake to compile llvm-rt but doesn't
   # use it for the normal build. This disables cmake in Nix.
   dontUseCmakeConfigure = true;
 
-  # ps is needed for one of the test cases
   nativeBuildInputs = [
-    file python2 ps rustPlatform.rust.rustc git cmake
-    which libffi removeReferencesTo
-    pkgconfig
-  ] # Only needed for the debuginfo tests
-    ++ optional (!stdenv.isDarwin) gdb;
+    file python2 rustPlatform.rust.rustc git cmake
+    which libffi removeReferencesTo pkgconfig
+  ];
 
   buildInputs = [ openssl ]
     ++ optional stdenv.isDarwin Security
@@ -169,29 +130,6 @@ in stdenv.mkDerivation rec {
   outputs = [ "out" "man" "doc" ];
   setOutputFlags = false;
 
-  # Disable codegen units and hardening for the tests.
-  preCheck = ''
-    export RUSTFLAGS=
-    export TZDIR=${tzdata}/share/zoneinfo
-    export hardeningDisable=all
-  '' +
-  # Ensure TMPDIR is set, and disable a test that removing the HOME
-  # variable from the environment falls back to another home
-  # directory.
-  optionalString stdenv.isDarwin ''
-    export TMPDIR=/tmp
-    sed -i '28s/home_dir().is_some()/true/' ./src/test/run-pass/env-home-dir.rs
-  '';
-
-  # 1. Upstream is not running tests on aarch64:
-  # see https://github.com/rust-lang/rust/issues/49807#issuecomment-380860567
-  # So we do the same.
-  # 2. Tests run out of memory for i686
-  #doCheck = !stdenv.isAarch64 && !stdenv.isi686;
-
-  # Disabled for now; see https://github.com/NixOS/nixpkgs/pull/42348#issuecomment-402115598.
-  doCheck = false;
-
   # remove references to llvm-config in lib/rustlib/x86_64-unknown-linux-gnu/codegen-backends/librustc_codegen_llvm-llvm.so
   # and thus a transitive dependency on ncurses
   postInstall = ''