python3Packages.glean-sdk: apply patch for process environments

pkgs/development/python-modules/glean-sdk/default.nix

@@ -3,6 +3,7 @@
 , python3Packages
 , rustPlatform
 , setuptools-rust
+, fetchpatch
 }:
 
 python3Packages.buildPythonPackage rec {
@@ -14,6 +15,12 @@ python3Packages.buildPythonPackage rec {
     sha256 = "sha256-X2p6KQnEB6ZHdCHGFVEoEMiI+0R2vfGqel+jFKTcx74=";
   };
 
+  patches = [
+    # Fix the environment for spawned process
+    # https://github.com/mozilla/glean/pull/1542
+    ./pr-1542.patch
+  ];
+
   cargoDeps = rustPlatform.fetchCargoTarball {
     inherit src;
     name = "${pname}-${version}";

pkgs/development/python-modules/glean-sdk/pr-1542.patch

@@ -0,0 +1,20 @@
+diff --git a/glean-core/python/glean/_process_dispatcher.py b/glean-core/python/glean/_process_dispatcher.py
+index 33a8b12796..a39b54a917 100644
+--- a/glean-core/python/glean/_process_dispatcher.py
++++ b/glean-core/python/glean/_process_dispatcher.py
+@@ -120,8 +120,14 @@ def dispatch(cls, func, args) -> Union[_SyncWorkWrapper, subprocess.Popen]:
+                     Path(".coveragerc").absolute()
+                 )
+ 
++            # Explicitly pass the contents of `sys.path` as `PYTHONPATH` to the
++            # subprocess so that there aren't any module search path
++            # differences.
++            python_path = ":".join(sys.path)[1:]
++
+             p = subprocess.Popen(
+-                [sys.executable, _process_dispatcher_helper.__file__, payload]
++                [sys.executable, _process_dispatcher_helper.__file__, payload],
++                env={"PYTHONPATH": python_path},
+             )
+ 
+             cls._last_process = p