pkg-config: Fix MinGW build

- MinGW build of pkg-config was failing due to fprintf format
errors (-Werror=format=, see
https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wformat).
  - Added "-Wno-error=format" flag to silence this error.

1 files changed, 6 insertions, 2 deletions

diff --git a/pkgs/development/tools/misc/pkg-config/default.nix b/pkgs/development/tools/misc/pkg-config/default.nix
index 5da91bccc1205..221e28cc8e418 100644
--- a/pkgs/development/tools/misc/pkg-config/default.nix
+++ b/pkgs/development/tools/misc/pkg-config/default.nix
@@ -35,8 +35,12 @@ stdenv.mkDerivation rec {
          "ac_cv_func_posix_getgrgid_r=yes"
        ];
 
-  # Silence "incompatible integer to pointer conversion passing 'gsize'" when building with Clang.
-  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-int-conversion";
+  env.NIX_CFLAGS_COMPILE = builtins.toString (
+    # Silence "incompatible integer to pointer conversion passing 'gsize'" when building with Clang.
+    lib.optionals stdenv.cc.isClang ["-Wno-int-conversion"] ++
+    # Silence fprintf format errors when building for Windows.
+    lib.optionals stdenv.hostPlatform.isWindows ["-Wno-error=format"]
+  );
 
   enableParallelBuilding = true;
   doCheck = true;