Dual-Root Mismatch in RustPython:
Unlike CPython, RustPython manages the standard library
in two separate locations in the workspace:
- Workspace 'Lib/': Contains the test suite ('Lib/test/...') and
standard library files.
- crates/pylib/Lib/: A helper directory used for packaging.
'crates/pylib/Lib' is a symlink pointing to the real workspace '../../Lib/'.
Runtime Directory Discrepancy:
- 'sys.path' contains 'crates/pylib/Lib' (the path to the symlink).
- Thus, when 'test.support' is imported, its '__file__' is resolved relative
to the symlink: '/opt/RustPython/crates/pylib/Lib/test/support/__init__.py'.
- Consequently, 'STDLIB_DIR' resolves to the symlink root:
'/opt/RustPython/crates/pylib/Lib'.
- However, since 'test_program.py' is executed directly from the workspace,
its 'pkg_dir' is: '/opt/RustPython/Lib/test/test_unittest/testmock'.
- When 'os.path.relpath(pkg_dir, top_dir)' is called:
---
os.path.relpath(
"/opt/RustPython/Lib/test/test_unittest/testmock",
"/opt/RustPython/crates/pylib/Lib"
)
# Result: "../../../Lib/test/test_unittest/testmock"
---
Because the relative path starts with '..', the assertion fails.
Assisted-by: Gemini
Leesoo Ahn