`importlib-metadata` breaks code

[lzchen]

          Was there a need to unconditionally use `importlib-metadata`, even on Python >= 3.10? This change broke my application framework (Asphalt) because it does `isinstance(value, EntryPoint)`, checking against `importlib.metadata.EntryPoint`, but after `importlib_metadata` is imported, iterating entry points (even through the stdlib facilities) yields `EntryPoint` instances from that third party library, which are NOT compatible with the stdlib ones!

EDIT: I see that importlib.metadata.EntryPoint is not directly documented in the API docs.

Originally posted by @agronholm in #3167 (comment)

[agronholm]

Given that importlib.metadata is no longer provisional in Python 3.10, its API is stable, so the workaround should only be used for Python 3.9 and earlier.

[mvilanova]

Pinning to 1.16.0 temporarily fixed the issue for us in Python 3.11.

[aabmass]

Given that importlib.metadata is no longer provisional in Python 3.10, its API is stable, so the workaround should only be used for Python 3.9 and earlier.

That makes sense to me 👍

Just to make sure I understand @agronholm, your original description of the issue does not sound like an issue with OpenTelemetry's usage of the library. It kind of sounds like an issue in either Asphalt (you mentioned EntryPoint is not documented looks fixed in this commit) in combination with some weird side effects between importlib.metadata and importlib-metadata.

Is that right?

[agronholm]

Just to make sure I understand @agronholm, your original description of the issue does not sound like an issue with OpenTelemetry's usage of the library. It kind of sounds like an issue in either Asphalt (you mentioned EntryPoint is not documented looks fixed in this commit) in combination with some weird side effects between importlib.metadata and importlib-metadata.

Yeah, it was only after upgrading the opentelemetry libs to 0.38b0 that I encountered this issue. Asphalt itself only uses the backport on Python 3.9 and earlier. It's not needed on 3.10 or later, and is just extra baggage there. I don't know if anybody is doing isinstance() with EntryPoint elsewhere, but if they do, they'll encounter the same issue.

[agronholm]

At any rate, the latest Asphalt no longer uses the EntryPoint class for comparisons so it's not an issue for me any longer.

[aabmass]

@mvilanova did you encounter this outside of Asphalt? If not I think we should close this bug and open a separate one to make it conditional import for python<3.10

[jsjeannotte]

Hi folks! Any update on this? We're still stuck with pinning to 1.16.0 and would love to un-pin.