Much of the dynamic logic insetup.py serves the purpose of stamping the package version into__version__, which starts out as"git". When, or before, the project definition is made declarative, as discussed in comments in#1716, the version stamping logic needs to be removed.

From the discussion there, it seems a goal is to havepyproject.toml become the single source of the version, and to useimportlib.metadata to retrieve it when accessed asgit.__version__ (with theimportlib_metadata backport used on 3.7).

Changes in#1886 have the additional effect of making it so this can be done at any time, since there is already a mechanism in place, and in use for some other attributes, to provide dynamically computed attributes of the top-levelgit module, and already tests to verify that other attribute access there, and the robustness of static type checking, are not broken by it.

The question is what the logic should actually be. A common and straightforward approach is to simply useimportlib.metadata.version on the known package name to always return the version from when the package was installed (whether that was from a local directory, editably or not, or from an sdist or wheel, obtained automatically from PyPI or otherwise). For example,thejsonschema library contains this code:

def__getattr__(name):ifname=="__version__":warnings.warn("Accessing jsonschema.__version__ is deprecated and will be ""removed in a future release. Use importlib.metadata directly ""to query for jsonschema's version.",DeprecationWarning,stacklevel=2,        )fromimportlibimportmetadatareturnmetadata.version("jsonschema")elif ...

This can of course be done without deprecating__version__ by simply omitting the warning.

However, it may not always work quite how one wants. For example, if one makes an editable install, and then pulls changes that increase the version number, the old version number that was installed with will still be used. This could be confusing, and this sort of thing may have been part of why the complex version stamping logic insetup.py was introduced, or perhaps more likely, of why it has been kept.

I believe, though, that we can achieve something effectively equivalent to that, by using other facilities ofimportlib.metadata, and other metadata such as the__file__ variable, to check for the same conditions under which the version would have been stamped, return it in those cases, and otherwise return"git" instead, as with version stamping.

That the version"git" is used is itself potentially confusing, since, for example, when installing from a commit, branch, or tag by givingpip agit+https:// URL -- as well as simply doing a non-editable install from a clone and accessing it from a directory other than the root of the repository's working tree -- one already gets the stamped version number originally fromVERSION, rather than"git". However, on the whole, itmay be that this behavior is desirable and ought to be preserved so long as doing so does not turn out to be excessively complex.

If GitPython is also to deprecate__version__, then of course that should not be done. The simpler approach would certainly be best then, I would say. However, as noted in#1716 (comment), the readmecurrently says to reportgit.__version__ when reporting bugs, so if it is to be deprecated then that should be removed or changed to some other recommendation.

What should be done here?