pure: stringify builtin exception messages Builtin exceptions usually want strings, and display with a wierd b'' prefix if given bytes.

httppeer: avoid another bad reference before assignment warning This wasn't a problem, because `b''` from the `AttributeError` handler is in `bundle2.bundletypes`, so the following loop and conditional always run at least once. But PyCharm can't figure that out on its own, and it took a little exploring to figure out it wasn't a problem. The usage in `bundle2.writebundle` is to look it up in the map of bundle types, so it will break in a more obvious way in the unlikely event that the empty string is removed from the map in the future.

httppeer: move a variable to avoid a bad reference before assignment warning No actual bug here, because the conditional used to assign is the same as the conditional in the `finally` block that guards the reference.

httppeer: simplify two-way stream cleanup No need to conditionalize the cleanup if the filename is assigned outside the exception handler. I suppose `fd` leaks if `os.fdopen()` fails, but that was the case before too (and may trigger another exception in the `finally` block on Windows, when the file is still open).

rustfmt: update expected Rust edition In this case it doesn't change anything, but we've been using 2021 for a while now.

hghave: update expected rustfmt version We still use nightly, but have moved to a newer nightly after the last CI image upgrade in 74f1bf147a6d and 3876d4c6c79e.

rustfmt: apply formatting expected by newer nightly version This was missed in 3876d4c6c79ec5c71e8c51b876cc157e93a5eaac somehow.

tests: stop skipping `mercurial/pure/osutil.py` during pytype runs Not sure when the original issue(s) were fixed, but it works for me now.

largefiles: avoid a potentially undefined variable in exception case The `wlock` variable is used to release the lock in the `finally` block, so it would be undefined if `repo.wlock()` itself failed. Caught by pytype 2024.04.11 with py3.10.11.

typing: add trivial type hints to `mercurial.scmutil` There's still a lot to go, but there's a lot here already, so I tried to keep it to obvious/trivial things. I didn't bother with contexts, matchers, and revisions that can be `bytes | int | None`.

typing: narrow the scope of some recent disabled import warnings These comments were added in 39e2b2d062c1, but had the effect of changing the known type to `Any`, which cascaded through a few function signatures. Just ignore the import error instead.

demandimport: don't delay threading import A recent cpython change breaks demandimport by importing threading locally in importlib.util.LazyLoader.exec_module; add it (plus warnings and _weakrefset, which are imported by threading) to demandimport's ignore list. ``` Traceback (most recent call last): File "/usr/bin/hg", line 57, in <module> from mercurial import dispatch File "<frozen importlib._bootstrap>", line 1360, in _find_and_load File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 935, in _load_unlocked File "/usr/lib/python3/dist-packages/hgdemandimport/demandimportpy3.py", line 52, in exec_module super().exec_module(module) File "<frozen importlib.util>", line 257, in exec_module File "<frozen importlib._bootstrap>", line 1360, in _find_and_load File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 935, in _load_unlocked File "/usr/lib/python3/dist-packages/hgdemandimport/demandimportpy3.py", line 52, in exec_module super().exec_module(module) File "<frozen importlib.util>", line 267, in exec_module AttributeError: partially initialized module 'threading' has no attribute 'RLock' (most likely due to a circular import) ``` Ref: https://github.com/python/cpython/issues/117983 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1076449 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1076747

typing: induce pytype to use the standard `attr` instead of the vendored copy What was previously happening with the vendored copy was that pytype would stub out all(?) classes that were decorated with `@attr.s` as `Any`. After this, we get a ton of classes defined, and numerous fields and methods now have proper types.

typing: disable some pytype errors in `mercurial.store` These seem to be legitimate errors, since one of the two callers (`encodedstore.data_entries()`) was previously typed to generate `BaseStoreEntry`. However, that and the other caller only pass `RevlogStoreEntry` objects. I can't tell if this was a WIP or what, but don't want to get side tracked on this. So flag as a TODO for later.

linelog: correct the default value of `annotateresult.lines` This was flagged by pytype once it was tricked into using the standard `attr` package instead of the vendored copy.