From ceed1e28400a73e1bb2e18cc20ff1683056e6ab5 Mon Sep 17 00:00:00 2001
From: Patrick Mahoney <pat@polycrystal.org>
Date: Sat, 12 Jun 2021 09:05:08 -0500
Subject: [PATCH] faust: fix compiler flags when used outside nix shell

Fixes https://github.com/NixOS/nixpkgs/issues/78610

The issue is some additional environment variables added to the nix
compiler wrappers that also need to be exported by the faust
wrapper.

This "wrapWithBuildEnv" solution is very hacky, but I
don't know of a better solution.
---
 pkgs/applications/audio/faust/faust2.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/applications/audio/faust/faust2.nix b/pkgs/applications/audio/faust/faust2.nix
index 995618af4ce5..c1d351fa53e1 100644
--- a/pkgs/applications/audio/faust/faust2.nix
+++ b/pkgs/applications/audio/faust/faust2.nix
@@ -178,6 +178,12 @@ let
 
         # export parts of the build environment
         for script in "$out"/bin/*; do
+          # e.g. NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu
+          nix_cc_wrapper_target_host="$(printenv | grep ^NIX_CC_WRAPPER_TARGET_HOST | sed 's/=.*//')"
+
+          # e.g. NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu
+          nix_bintools_wrapper_target_host="$(printenv | grep ^NIX_BINTOOLS_WRAPPER_TARGET_HOST | sed 's/=.*//')"
+
           wrapProgram "$script" \
             --set FAUSTLDDIR "${faust}/lib" \
             --set FAUSTLIB "${faust}/share/faust" \
@@ -187,7 +193,9 @@ let
             --prefix PKG_CONFIG_PATH : "$PKG_CONFIG_PATH" \
             --set NIX_CFLAGS_COMPILE "$NIX_CFLAGS_COMPILE" \
             --set NIX_LDFLAGS "$NIX_LDFLAGS -lpthread" \
-            --prefix LIBRARY_PATH $libPath
+            --set "$nix_cc_wrapper_target_host" "''${!nix_cc_wrapper_target_host}" \
+            --set "$nix_bintools_wrapper_target_host" "''${!nix_bintools_wrapper_target_host}" \
+            --prefix LIBRARY_PATH "$libPath"
         done
       '';
     });