pyupgrade: drop usage of py3 aliases for `OSError` These were different classes in py2, but now a handful of error classes are just an alias of `OSError`, like `IOError`, `EnvironmentError`, `WindowsError`, etc. This is the result of running a hacked version of `pyupgrade` 3.19.1[1] $ hg files -0 'relglob:**.py' | xargs -0 \ pyupgrade --py38-plus --keep-percent-format --keep-mock --keep-runtime-typing The hack is because it doesn't have command line switches to disable most changes, so it makes tons of unrelated changes all at once. The hack is to 1) patch `pyupgrade._main._fix_tokens()` to immediately return its content arg 2) change `pyupgrade._data.register_decorator()` to only register the function if it's from the fixer we're interested in: if func.__module__ in ( "pyupgrade._plugins.exceptions", ): FUNCS[tp].append(func) return func [1] https://github.com/asottile/pyupgrade

--- a/mercurial/win32.py	Mon Jan 06 14:15:40 2025 -0500
+++ b/mercurial/win32.py	Sun Jan 05 21:03:17 2025 -0500
@@ -718,7 +718,7 @@
     if os.path.isdir(path):
         # use EPERM because it is POSIX prescribed value, even though
         # unlink(2) on directories returns EISDIR on Linux
-        raise IOError(
+        raise OSError(
             errno.EPERM,
             r"Unlinking directory not permitted: '%s'"
             % encoding.strfromlocal(path),
@@ -749,7 +749,7 @@
         except FileExistsError:
             pass
     else:
-        raise IOError(errno.EEXIST, "No usable temporary filename found")
+        raise OSError(errno.EEXIST, "No usable temporary filename found")
 
     try:
         os.unlink(temp)