shelve: consistently convert exception to bytes via `stringutil.forcebytestr` The other two places in this module use this, and past experience shows that this method does a nicer job. I'm not sure why we're converting to bytes here- `KeyError` is built-in and will have str attrs, and `RepoLookupError` is a subclass of the built-in `Exception` class (not `errors.Error`, which is allegedly the baseclass for all Mercurial exceptions).

typing: add type hints to `mercurial.shelve` Pytype wasn't flagging anything here yet, but PyCharm was really unhappy about the usage of `state` objects being passed to various methods that accessed attrs on it, without any obvious attrs on the class because there's no contructor. Filling that out made PyCharm happy, and a few other things needed to be filled in to make that easier, so I made a pass over the whole file and filled in the trivial hints. The other repo, ui, context, matcher, and pats items can be filled in after the context and match modules are typed.

typing: lock in correct changes from pytype 2023.04.11 -> 2023.06.16 There were a handful of other changes to the pyi files generated when updating pytype locally (and jumping from python 3.8.0 to python 3.10.11), but they were not as clear (e.g. the embedded type in a list changing from `nothing` to `Any` or similar). These looked obviously correct, and agreed with PyCharm's thoughts on the signatures. Oddly, even though pytype starting inferring `obsutil._getfilteredreason()` as returning bytes, it (correctly) complained about the None path when it was typed that way. Instead, raise a ProgrammingError if an unhandled fate is calculated. (Currently, all possibilities are handled, so this isn't reachable unless another fate is added in the future.)

monotone: replace %s interpolation with appropriate numeric specifiers The length is an int, and the version is a float. Neither work with bytes on py3. This was noticed when looking at nearby code after updating pytype changed some signatures.

shelve: raise an error when loading a corrupt state file in an impossible case The old return statement was flagged by pytype 2023.06.16 running under python 3.10.11. No idea why it isn't caught in CI running the same pytype with py3.7. This function is only called by `unshelvecmd()` (which first checks that either `--abort` or `--continue` is specified), and `hgabortunshelve()` and `hgcontinueunshelve()`, which locally apply `--abort` or `--continue` respectively. Therefore, there is no other way to call this, and this error should never be seen, but pytype can't figure that out on its own. Given that the abort case clears the state, it seems reasonable to defensively code this and not make that a blanket `else` case, on the off chance a 3rd way of calling this appears in the future.

contrib: print the version of pytype used to do the type checking This will help with CI. I don't see a way to print the version of python that's running it. When I tried `head -n 1 $(which pytype)`, the CI run printed: #!/usr/bin/env bash Locally, that gives the path to the python interpreter in the venv, so IDK what's different.

typing: create an @overload of `phasecache` ctor to handle the copy case In `phasecache.copy()`, it calls `self.__class__(None, None, _load=False)`, but the constuctor is typed to take a non-None repository. For the `_load=False` case, all args are ignored (and the copy function itself populates the attrs on the new object), so this isn't an error. For the default `_load=True` case, it needs a non-None repository. This is the simplest way to handle that duality. The reason this wasn't being detected is because pytype is confused by the interface decorators on the `localrepository` class, and is inferring the whole class as `Any`. (See 3e9a660b074a or c1d7ac70980b) Therefore, the type hint of `localrepo.localrepository` here was also effectively `Any`, which disabled the type checking entirely. This is the first foray into using `typing_extensions` to unlock future typing features. I think this is safe and reasonable because 1) it is only imported in the type checking phase (so no need to vendor our own copy), and 2) pytype has its own copy of `typing_extensions` bundled with it, so no need to alter the test environment. When run with a version of python that supports the symbol(s) natively, `typing_extensions` simply re-exports from `typing`, so there shouldn't be any future headaches with this.

typing: declare the `_phasesets` member of `phasecache` to be `Optional` Something in this area got flagged while making the repository class visible to pytype (instead of being typed as `Any`). A None assignment to something not optional is wrong, and when I tried setting it to `{}` to keep it non-Optional, some tests failed. There are checks for the attr being None elsewhere, so this seems to have just been an oversight.

typing: hide the interface version of `dirstate` during type checking As noted in the previous commit, the `dirstate` type is still inferred as `Any` by pytype, including where it is used as a base class for the largefiles dirstate. That effectively disables most type checking. The problems fixed two commits ago were flagged by this change. I'm not at all clear what the benefit of the original type is, but that was what was used at runtime, so I don't want to change the largefiles base class to the raw class. Having both a lowercase and camelcase name for the same thing isn't great, but given that this trivially finds problems without worrying about which symbol clients may be using, and the non-raw type is useless to pytype anyway, I'm not going to worry about it.

dirstate: remove the interface decorator to help pytype This is the same change that was made for some of the manifest classes in 3e9a660b074a. Note that `dirstate` is still inferred as `Any`, but at least we have `DirState` with all of the expected attributes.