Propagating debug source db to test process via env

Summary: `dbg-db.json` contains the right source mapping for python unittest file. we inject the source mapping file path via env into the test environement

Reviewed By: patskovn

Differential Revision: D67856724

fbshipit-source-id: 08763b9ee36475e4d27a227b390a7538681a42e9

prelude/python/make_py_package.bzl

@@ -61,6 +61,7 @@ PexProviders = record(
     hidden_resources = list[ArgLike],
     sub_targets = dict[str, list[Provider]],
     run_cmd = cmd_args,
+    dbg_source_db = field(Artifact | None, None),
 )
 
 ManifestModule = record(

prelude/python/python_binary.bzl

@@ -398,6 +398,16 @@ def python_executable(
         dbg_source_db_output,
     )
 
+    exe = PexProviders(
+        default_output = exe.default_output,
+        other_outputs = exe.other_outputs,
+        other_outputs_prefix = exe.other_outputs_prefix,
+        hidden_resources = exe.hidden_resources,
+        sub_targets = exe.sub_targets,
+        run_cmd = exe.run_cmd,
+        dbg_source_db = dbg_source_db_output,
+    )
+
     exe.sub_targets.update({
         "dbg-source-db": [dbg_source_db],
         "library-info": [library_info],

prelude/python/python_test.bzl

@@ -73,13 +73,16 @@ def python_test_impl(ctx: AnalysisContext) -> list[Provider]:
 
     # Setup RE executors based on the `remote_execution` param.
     re_executor, executor_overrides = get_re_executors_from_props(ctx)
+    test_env = ctx.attrs.env
+    if pex.dbg_source_db:
+        test_env["PYTHON_SOURCE_MAP"] = pex.dbg_source_db
 
     return inject_test_run_info(
         ctx,
         ExternalRunnerTestInfo(
             type = "pyunit",
             command = [test_cmd],
-            env = ctx.attrs.env,
+            env = test_env,
             labels = ctx.attrs.labels,
             contacts = ctx.attrs.contacts,
             default_executor = re_executor,