Certain tests can't deal with symlinks on Windows

[wyattscarpenter]

I'm running the tests in a directory that I got to using a symlink. It is now complaining that the output isn't right on some tests, since apparently the absolute path is reported instead of the symlinky one it expects. I'm running from a venv, and also on windows 10. (The symlink is a symlinkd, which I mention because windows sadly has like 4 different types of symlink. But I doubt it's relevant.) I tried to replicate this on WSL2 (Ubuntu) but couldn't.

Here are the test failures of uv run runtests.py pytest-fast:

================================================================================================================= FAILURES =================================================================================================================
_______________________________________________________________________________________________________ testNamedTupleAdditionalArgs _______________________________________________________________________________________________________
[gw3] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\check-namedtuple.test:118:
Failed: Unexpected type checker output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\check-namedtuple.test, line 118)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  main:4: error: Boolean literal expected as the "rename" argument to namedtuple()
  main:5: error: Boolean literal expected as the "rename" argument to namedtuple()
  main:5: error: Argument "rename" to "namedtuple" has incompatible type "str"; expected "int"
  main:6: error: Unexpected keyword argument "unrecognized_arg" for "namedtuple"
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/collections.pyi:3: note: "namedtuple" defined here (diff)
  main:7: error: Too many positional arguments for "namedtuple"
Actual:
  main:4: error: Boolean literal expected as the "rename" argument to namedtuple()
  main:5: error: Boolean literal expected as the "rename" argument to namedtuple()
  main:5: error: Argument "rename" to "namedtuple" has incompatible type "str"; expected "int"
  main:6: error: Unexpected keyword argument "unrecognized_arg" for "namedtuple"
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/collections.pyi:3: note: "namedtuple" defined here (diff)
  main:7: error: Too many positional arguments for "namedtuple"

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/collections.pyi:3:...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/collection...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
______________________________________________________________________________________________ testImportBringsAnotherFileWithBlockingError1 _______________________________________________________________________________________________
[gw3] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:400:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 400)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:1: error: "int" not callable
Actual:
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:1: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: err...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.py...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
_______________________________________________________________________________________ testImportBringsAnotherFileWithSemanticAnalysisBlockingError _______________________________________________________________________________________
[gw3] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:420:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 420)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker2.pyi:2: error: "continue" outside loop (diff)
  ==
  a.py:1: error: "int" not callable
Actual:
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker2.pyi:2: error: "continue" outside loop (diff)
  ==
  a.py:1: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker2.pyi:2: er...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker2.p...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
_________________________________________________________________________________________ testFixingBlockingErrorBringsInAnotherModuleWithBlocker __________________________________________________________________________________________
[gw3] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:474:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 474)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  a.py:1: error: Invalid syntax
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:2: error: "int" not callable
Actual:
  ==
  a.py:1: error: Invalid syntax
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:2: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: err...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.py...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
________________________________________________________________________________________________ testAddFileWhichImportsLibModuleWithErrors ________________________________________________________________________________________________
[gw3] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-modules.test:754:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-modules.test, line 754)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  main:2: error: Cannot find implementation or library stub for module named "a"
  main:2: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
  ==
  a.py:3: error: Name "z" is not defined
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/broken.pyi:2: error: Name "y" is not defined (diff)
Actual:
  main:2: error: Cannot find implementation or library stub for module named "a"
  main:2: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
  ==
  a.py:3: error: Name "z" is not defined
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/broken.pyi:2: error: Name "y" is not defined (diff)

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/broken.pyi:2: erro...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/broken.pyi...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
___________________________________________________________________________________________ testImportBringsAnotherFileWithBlockingError1_cached ___________________________________________________________________________________________
[gw2] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:400:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 400)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:1: error: "int" not callable
Actual:
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:1: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: err...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.py...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
___________________________________________________________________________________ testImportBringsAnotherFileWithSemanticAnalysisBlockingError_cached ____________________________________________________________________________________
[gw2] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:420:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 420)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker2.pyi:2: error: "continue" outside loop (diff)
  ==
  a.py:1: error: "int" not callable
Actual:
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker2.pyi:2: error: "continue" outside loop (diff)
  ==
  a.py:1: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker2.pyi:2: er...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker2.p...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
______________________________________________________________________________________ testFixingBlockingErrorBringsInAnotherModuleWithBlocker_cached ______________________________________________________________________________________
[gw2] win32 -- Python 3.9.22 C:\Users\wyatt\files\tmp\mypy\.venv\Scripts\python.exe
data: C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test:474:
Failed: Invalid output (C:\Users\wyatt\files\tmp\mypy\test-data\unit\fine-grained-blockers.test, line 474)
----------------------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------------------
Expected:
  ==
  a.py:1: error: Invalid syntax
  ==
  C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:2: error: "int" not callable
Actual:
  ==
  a.py:1: error: Invalid syntax
  ==
  C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax (diff)
  ==
  a.py:2: error: "int" not callable

Alignment of first line difference:
  E: C:/Users/wyatt/files/tmp/mypy/test-data/unit/lib-stub/blocker.pyi:2: err...
  A: C:/Users/wyatt/files/tmp/mypy_symlink/test-data/unit/lib-stub/blocker.py...
                                  ^
Update the test output using --update-data (implies -n0; you can additionally use the -k selector to update only specific tests)
========================================================================================================= short test summary info ==========================================================================================================
FAILED mypy/test/testcheck.py::TypeCheckSuite::check-namedtuple.test::testNamedTupleAdditionalArgs
FAILED mypy/test/testfinegrained.py::FineGrainedSuite::fine-grained-blockers.test::testImportBringsAnotherFileWithBlockingError1
FAILED mypy/test/testfinegrained.py::FineGrainedSuite::fine-grained-blockers.test::testImportBringsAnotherFileWithSemanticAnalysisBlockingError
FAILED mypy/test/testfinegrained.py::FineGrainedSuite::fine-grained-blockers.test::testFixingBlockingErrorBringsInAnotherModuleWithBlocker
FAILED mypy/test/testfinegrained.py::FineGrainedSuite::fine-grained-modules.test::testAddFileWhichImportsLibModuleWithErrors
FAILED mypy/test/testfinegrainedcache.py::FineGrainedCacheSuite::fine-grained-blockers.test::testImportBringsAnotherFileWithBlockingError1_cached
FAILED mypy/test/testfinegrainedcache.py::FineGrainedCacheSuite::fine-grained-blockers.test::testImportBringsAnotherFileWithSemanticAnalysisBlockingError_cached
FAILED mypy/test/testfinegrainedcache.py::FineGrainedCacheSuite::fine-grained-blockers.test::testFixingBlockingErrorBringsInAnotherModuleWithBlocker_cached
8 failed, 11353 passed, 301 skipped, 8 xfailed in 418.89s (0:06:58)

[wyattscarpenter]

I was able to replicate on my other machine, which has Windows 11 with python 3.13.