go: fix on darwin, make go-1.7 build with clang-3.8. (#18001)

The darwin stdenv currently provides clang-3.7; however,

  a) go-1.7 currently expects a compiler that supports "-fdebug-prefix-map"
     arguments (which clang-3.8 supports but clang-3.7 does not) and

  b) even with clang-3.8, go-1.7 misinterprets the result of its runtime probes
     for support for the "-no-pie" flag, thereby failing to build runtime/cgo.

This patch resolves (a) by building go-1.7 with clang-3.8 and resolves (b) by
teaching go how to correctly probe "-no-pie" error messages from clang.

1 files changed, 4 insertions, 2 deletions

diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 4c9f8dc5ca3d..66f1667dc32f 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -4738,9 +4738,11 @@ in
     inherit (darwin.apple_sdk.frameworks) Security Foundation;
   };
 
-  go_1_7 = callPackage ../development/compilers/go/1.7.nix {
+  go_1_7 = callPackage ../development/compilers/go/1.7.nix ({
     inherit (darwin.apple_sdk.frameworks) Security Foundation;
-  };
+  } // stdenv.lib.optionalAttrs stdenv.isDarwin {
+    stdenv = stdenvAdapters.overrideCC pkgs.stdenv pkgs.clang_38;
+  });
 
   go = self.go_1_7;