python3Packages.rembg: fix cuda build

Author: GaetanLepage

pkgs/development/python-modules/rembg/default.nix

@@ -33,8 +33,12 @@
 
   # tests
   versionCheckHook,
+  pocl,
 
   withCli ? false,
+  config,
+  cudaSupport ? config.cudaSupport,
+  writableTmpDirAsHomeHook,
 }:
 
 let
@@ -102,6 +106,12 @@ buildPythonPackage (finalAttrs: {
   # not running python tests, as they require network access
   nativeCheckInputs = lib.optionals withCli [
     versionCheckHook
+  ] ++ lib.optionals cudaSupport [
+    # Provides a CPU-based OpenCL ICD so that pyopencl's module-level
+    # cl.create_some_context() succeeds without GPU hardware.
+    pocl
+    # pocl needs a writable $HOME for its kernel cache directory.
+    writableTmpDirAsHomeHook
   ];
   versionCheckKeepEnvironment = [
     # Otherwise, fail with: