From 93d523cb03f9b5816aa79053dbdd2ff3110c37ed Mon Sep 17 00:00:00 2001
From: David McFarland <corngood@gmail.com>
Date: Thu, 9 Oct 2025 10:25:12 -0300
Subject: [PATCH] file: fix cross build for windows platforms

This should be a more general fix than the original windows one.  This
is needed because upstream uses `EXEEXT` for build stuff:

    # FIXME: Build file natively as well so that it can be used to compile
    # the target's magic file; for now we bail if the local version does not
    match
    if IS_CROSS_COMPILE
    FILE_COMPILE = file${EXEEXT}
    FILE_COMPILE_DEP =
    else
    FILE_COMPILE = $(top_builddir)/src/file${EXEEXT}
    FILE_COMPILE_DEP = $(FILE_COMPILE)
    endif
---
 pkgs/tools/misc/file/default.nix | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/pkgs/tools/misc/file/default.nix b/pkgs/tools/misc/file/default.nix
index c96214519966..34f58c1f92a8 100644
--- a/pkgs/tools/misc/file/default.nix
+++ b/pkgs/tools/misc/file/default.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  file,
+  buildPackages,
   zlib,
   libgnurx,
   updateAutotoolsGnuConfigScriptsHook,
@@ -51,14 +51,16 @@ stdenv.mkDerivation (finalAttrs: {
 
   nativeBuildInputs = [
     updateAutotoolsGnuConfigScriptsHook
-  ]
-  ++ lib.optional (stdenv.hostPlatform != stdenv.buildPlatform) file;
+  ];
   buildInputs = [ zlib ] ++ lib.optional stdenv.hostPlatform.isMinGW libgnurx;
 
   # https://bugs.astron.com/view.php?id=382
   doCheck = !stdenv.buildPlatform.isMusl;
 
-  makeFlags = lib.optional stdenv.hostPlatform.isWindows "FILE_COMPILE=file";
+  # In native builds, it will use the newly-compiled file instead.
+  makeFlags = lib.optional (
+    !lib.systems.equals stdenv.hostPlatform stdenv.buildPlatform
+  ) "FILE_COMPILE=${lib.getExe buildPackages.file}";
 
   passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;