fontforge: add an initial value for sys.path inside fontforge, rather than using a wrapper

Using a wrapper causes build failures on Darwin for some derivations like `dejavu-fonts`, and we don't need to do it.

pkgs/by-name/fo/fontforge/package.nix

@@ -3,10 +3,10 @@
   fetchFromGitHub,
   lib,
   fetchpatch,
+  replaceVars,
   cmake,
   uthash,
   pkg-config,
-  makeWrapper,
   python3,
   freetype,
   zlib,
@@ -74,6 +74,9 @@ stdenv.mkDerivation rec {
       url = "https://github.com/fontforge/fontforge/commit/2f2ba54c15c5565acbde04eb6608868cbc871e01.patch";
       hash = "sha256-qF4DqFpiZDbULi9+POPM73HF6pEot8BAFSVaVCNQrMU=";
     })
+
+    # Provide a Nix-controlled location for the initial `sys.path` entry.
+    (replaceVars ./set-python-sys-path.patch { python = "${py}/${py.sitePackages}"; })
   ];
 
   # use $SOURCE_DATE_EPOCH instead of non-deterministic timestamps
@@ -91,7 +94,6 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [
     pkg-config
     cmake
-    makeWrapper
   ];
 
   buildInputs =
@@ -131,10 +133,6 @@ stdenv.mkDerivation rec {
     export SOURCE_DATE_EPOCH=$(date -d ${version} +%s)
   '';
 
-  postInstall = lib.optionalString withPython ''
-    wrapProgram $out/bin/fontforge --suffix PYTHONPATH : "${py}/${py.sitePackages}"
-  '';
-
   meta = {
     description = "Font editor";
     homepage = "https://fontforge.github.io";

pkgs/by-name/fo/fontforge/set-python-sys-path.patch

@@ -0,0 +1,21 @@
+Author: Philip Taron <philip.taron@gmail.com>
+Date:   Sat Jan 4 12:22:38 2025 -0800
+
+    fontforge: add an initial value for `sys.path`
+
+diff --git a/fontforge/python.c b/fontforge/python.c
+index e18d77d43..2e312eeb4 100644
+--- a/fontforge/python.c
++++ b/fontforge/python.c
+@@ -19576,6 +19576,11 @@ void FontForge_InitializeEmbeddedPython(void) {
+     PyStatus status;
+     PyConfig_InitPythonConfig(&config);
+ 
++    status = PyConfig_SetBytesString(&config, &config.pythonpath_env, "@python@");
++    if (PyStatus_Exception(status)) {
++        fprintf(stderr, "Failed to set the Python search path: %s\n", status.err_msg);
++    }
++
+     status = PyConfig_SetBytesString(&config, &config.program_name,
+                                      "fontforge");
+     if (PyStatus_Exception(status)) {