Handle DistributionNotFound

[trollfred]

No description provided.

[codecov]

Codecov Report

Merging #594 into master will decrease coverage by 0.07%.
The diff coverage is 60%.

@@            Coverage Diff             @@
##           master     #594      +/-   ##
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- Coverage   95.64%   95.57%   -0.08%     
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  Files          20       20              
  Lines        2436     2439       +3     
  Branches      308      308              
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+ Hits         2330     2331       +1     
- Misses         93       95       +2     
  Partials       13       13

[Julian]

Hi. Thanks. What situation are you encountering that you're trying to fix here?

[trollfred]

hi @Julian! I'm packing it as a dependency with py2app and pkg_resources doesn't work there, so I thought some handling won't hurt, right?

[Julian]

So, understandable, but py2app isn't currently supported because it doesn't run in CI.

I'm perfectly happy to support it if it doesn't cause major issues, but it'd need to run in CI -- i.e., if you say added a tox environment that tries to build jsonschema, and that failed, and passed with this change, that's fine (even though py2app is doing something wrong there), but yeah as-is without coverage it's unfortunately not a supported configuration because I have no way of knowing whether some other future otherwise-totally correct change will break py2app.

[trollfred]

I still see two possibilities:

1. I could try adding a test case for py2app, gonna be complicated but ok
2. I could detect py2app and reraise DistributionNotFound if wasn't detected - this way this change will be 100% transparent for the rest of the world
   what do you think?

[Julian]

It's not about backwards compatibility -- all code changes have to have tests The test should essentially do whatever exact procedure someone would go through to run py2app

…

On Wed, Aug 14, 2019, 15:58 Igor Savchuk ***@***.***> wrote: I still see two possibilities: 1. I could try adding a test case for py2app, gonna be complicated but ok 2. I could detect py2app and reraise DistributionNotFound if wasn't detected - this way this change will be 100% transparent for the rest of the world what do you think? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#594>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AACQQXTVZKZFLK75KZGFWH3QEQFPJANCNFSM4IKTZKTQ> .

[Julian]

I don't know that it fixes the issue here (and again, much as I sympathize, I think "officially", this is still a not-really-supported configuration unless it's under CI), but you might find that the next release (3.1) happens to fix your issue here (because we've now moved to importlib-metadata instead of pkg_resources, which is the newer way to do what was done here before).

I don't know for sure that it fixes this, but it may.