pants package :pex doesn't remove source root prefix for generated resources

src/python/pants/backend/python/goals/run_pex_binary_integration_test.py

@@ -3,13 +3,19 @@
 from __future__ import annotations
 
 import json
+from pathlib import Path
 from textwrap import dedent
 from typing import Callable, Optional
 
 import pytest
 
 from pants.backend.python.target_types import PexExecutionMode, PexLayout
-from pants.testutil.pants_integration_test import PantsResult, run_pants, setup_tmpdir
+from pants.base.build_environment import get_buildroot
+from pants.testutil.pants_integration_test import (
+    PantsResult,
+    run_pants,
+    setup_tmpdir,
+)
 
 
 def run_generic_test(
@@ -309,3 +315,58 @@ def test_pass_extra_pex_cli_subsystem_global_args() -> None:
         stderr = result.stderr.strip()
         assert "unrecognized arguments" in stderr
         assert "non-existing-flag-name" in stderr
+
+
+def test_relocated_resources() -> None:
+    sources = {
+        "assets/query.sql": "SELECT 1",
+        "assets/BUILD": dedent(
+            """\
+            files(name='files', sources=['query.sql'])
+            """
+        ),
+        "src/py/project/__init__.py": "",
+        "src/py/project/app.py": dedent(
+            """\
+            from importlib.resources import files
+            import project
+
+            def main():
+                assert files(project).joinpath("query.sql").read_text() == "SELECT 1"
+            """
+        ),
+        "src/py/project/BUILD": dedent(
+            """\
+            python_sources()
+            relocated_files(
+                name='relocated',
+                files_targets=['assets:files'],
+                src='assets',
+                dest='src/py/project',
+            )
+            experimental_wrap_as_resources(name='resources', inputs=[':relocated'])
+            pex_binary(
+                name="binary",
+                dependencies=[':resources'],
+                entry_point="project.app:main",
+            )
+            """
+        ),
+        "pants.toml": "",
+    }
+
+    for relpath, content in sources.items():
+        path = Path(get_buildroot()).joinpath(relpath)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_text(content)
+
+    args = [
+        "--backend-packages=pants.backend.python",
+        "--source-root-patterns=['src/py']",
+        "--python-interpreter-constraints=['CPython>=3.9']",
+        "run",
+        "src/py/project:binary",
+    ]
+    result = run_pants(args, use_pantsd=False)
+
+    assert "No such file or directory" not in result.stderr, result.stderr

src/python/pants/backend/python/util_rules/python_sources.py

@@ -5,6 +5,7 @@
 
 from dataclasses import dataclass
 from typing import Iterable
+import sys
 
 from pants.backend.python.target_types import PythonSourceField
 from pants.backend.python.util_rules import ancestor_files
@@ -134,6 +135,7 @@ async def prepare_python_sources(
         )
         for tgt in codegen_targets
     )
+    sys.stderr.write(f"{codegen_sources=}\n")
     source_root_requests = [
         *(SourceRootRequest.for_target(tgt) for tgt in python_and_resources_targets),
         *(
@@ -142,11 +144,14 @@ async def prepare_python_sources(
             for f in sources.snapshot.files
         ),
     ]
+    sys.stderr.write(f"{source_root_requests=}\n")
 
     source_root_objs = await MultiGet(
         Get(SourceRoot, SourceRootRequest, req) for req in source_root_requests
     )
     source_root_paths = {source_root_obj.path for source_root_obj in source_root_objs}
+    sys.stderr.write(f"{sources.unrooted_files=}\n")
+    sys.stderr.write(f"{init_injected=}\n")
     return PythonSourceFiles(
         SourceFiles(init_injected, sources.unrooted_files), tuple(sorted(source_root_paths))
     )

src/python/pants/core/register.py

@@ -5,6 +5,7 @@
 
 These are always activated and cannot be disabled.
 """
+
 from pants.backend.codegen import export_codegen_goal
 from pants.build_graph.build_file_aliases import BuildFileAliases
 from pants.core.goals import (
@@ -63,7 +64,11 @@
 from pants.vcs import git
 from pants.version import PANTS_SEMVER
 
-wrap_as_resources = wrap_source_rule_and_target(ResourceSourceField, "resources")
+wrap_as_resources = wrap_source_rule_and_target(
+    ResourceSourceField,
+    "resources",
+    uses_source_roots=True,
+)
 
 
 def rules():

src/python/pants/core/util_rules/source_files.py

@@ -1,6 +1,7 @@
 # Copyright 2020 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
+import sys
 from dataclasses import dataclass
 from pathlib import PurePath
 from typing import Collection, Iterable, Set, Tuple, Type, Union
@@ -60,6 +61,8 @@ async def determine_source_files(request: SourceFilesRequest) -> SourceFiles:
     )
 
     for hydrated_sources, sources_field in zip(all_hydrated_sources, request.sources_fields):
+        sys.stderr.write(f"{type(sources_field)=}\n")
+        sys.stderr.write(f"{sources_field.uses_source_roots=}\n")
         if not sources_field.uses_source_roots:
             unrooted_files.update(hydrated_sources.snapshot.files)
 

src/python/pants/core/util_rules/wrap_source.py

@@ -45,6 +45,12 @@ class ActivateWrapSourceTargetFieldBase(MultipleSourcesField):
     uses_source_roots = False
     expected_num_files = 0
 
+class ActivateWrapSourceTargetFieldBase(MultipleSourcesField):
+    # We solely register so that codegen can match a fieldset.
+    # One unique subclass must be defined per target type.
+    alias = "_sources"
+    uses_source_roots = False
+    expected_num_files = 0
 
 class WrapSourceInputsField(SpecialCasedDependencies):
     alias = "inputs"
@@ -99,7 +105,9 @@ async def _wrap_source(wrapper: GenerateSourcesRequest) -> GeneratedSources:
 
 
 def wrap_source_rule_and_target(
-    source_field_type: type[SourcesField], target_name_suffix: str
+    source_field_type: type[SourcesField],
+    target_name_suffix: str,
+    uses_source_roots: bool = False,
 ) -> WrapSource:
     if source_field_type.expected_file_extensions:
         outputs_help = (