See for example this CI log. Failures:

=========================== short test summary info ============================
FAILED ../../f2py/tests/test_compile_function.py::test_f2py_init_compile[extra_args0]
FAILED ../../f2py/tests/test_compile_function.py::test_compile_from_strings[program test_f2py\nend program test_f2py0]
FAILED ../../f2py/tests/test_compile_function.py::test_compile_from_strings[program test_f2py\nend program test_f2py1]
FAILED ../../tests/test_public_api.py::test_import_lazy_import[testing] - Blo...
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_gh18684 - B...
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_gh6308 - Bl...
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_gh4519 - Bl...
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_gh3425 - Bl...
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_character_bc[new]
ERROR ../../f2py/tests/test_character.py::TestMiscCharacter::test_character_bc[old]
ERROR ../../f2py/tests/test_crackfortran.py::TestCrackFortran::test_gh2848 - ...
ERROR ../../f2py/tests/test_string.py::TestDocStringArguments::test_example
= 4 failed, 27912 passed, 203 skipped, 1306 deselected, 35 xfailed, 1 xpassed, 8 errors in 546.40s (0:09:06)

Cc @DWesl have you seen this before? May be due to the 22 Jan Cygwin release, not sure.