attrs 21.3.0 breaks coverage report on Python 3.6 (regression from 21.2.0)

[andersk]

With attrs 21.3.0, if I run a script that does import attr using coverage, I get an error from coverage report.

$ python3 --version
Python 3.6.15
$ echo 'import attr' > test.py
$ pip3 install attrs coverage
…
Successfully installed attrs-21.3.0 coverage-6.2
$ coverage run test.py
$ coverage report
No source for code: '/tmp/rep-1>'.

This worked with attrs 21.2.0.

$ pip3 install attrs==21.2.0
…
Successfully installed attrs-21.2.0
$ coverage run test.py
$ coverage report
Name      Stmts   Miss  Cover
-----------------------------
test.py       1      0   100%
-----------------------------
TOTAL         1      0   100%

I bisected the problem to commit 5a368d8 (#858). Cc @thetorpedodog @hynek.

[Tinche]

Interesting. Could be a coverage bug? Not sure why this would break it.

[deadlylaid]

python 3.7 has same issue

working in CI/CD

Running with gitlab-runner 14.6.0~beta.71.gf035ecbf (f035ecbf)
  on green-5.shared.runners-manager.gitlab.com/default xS6Vzpvo
Preparing the "docker+machine" executor
Using Docker executor with image python:3.7-slim-buster ...
Pulling docker image python:3.7-slim-buster ...

[...]

Collecting attrs>=19.2.0
  Downloading attrs-21.3.0-py2.py3-none-any.whl (61 kB)
[...]

coverage report -i
/usr/local/lib/python3.7/site-packages/coverage/report.py:87: CoverageWarning: Couldn't parse '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-10>': No source for code: '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-10>'. (couldnt-parse)
  coverage._warn(msg, slug="couldnt-parse")
/usr/local/lib/python3.7/site-packages/coverage/report.py:87: CoverageWarning: Couldn't parse '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-11>': No source for code: '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-11>'. (couldnt-parse)
  coverage._warn(msg, slug="couldnt-parse")
/usr/local/lib/python3.7/site-packages/coverage/report.py:87: CoverageWarning: Couldn't parse '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-12>': No source for code: '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-12>'. (couldnt-parse)
  coverage._warn(msg, slug="couldnt-parse")
/usr/local/lib/python3.7/site-packages/coverage/report.py:87: CoverageWarning: Couldn't parse '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-13>': No source for code: '/builds/Jade/jade/jadeapp/jade-rest-auth/rep-13>'. (couldnt-parse)

[...]

coverage xml
No source for code: '/builds/DeepNatural/deepnaturalai/deepapi/deepapi-rest-auth/rep-10>'.
make: *** [Makefile:37: coverage] Error 1

but when i fixed attrs==21.2.0, its work

[hynek]

@nedbat any idea? 🤔

[hynek]

OK, I think I've got it. Could y'all have a look at #896 and tell me if it fixes your problems? I can cut a release later today if yes.

[hynek]

JFTR: the reason why it didn't come up in my own tests is because I always set a --source:

$ coverage run test.py; coverage report
No source for code: '/Users/hynek/tmp/rep-1>'.
$ coverage run --source test test.py; coverage report
Name      Stmts   Miss  Cover
-----------------------------
test.py       1      0   100%
-----------------------------
TOTAL         1      0   100%

[andersk]

Yeah, #896 works for me, both in my minimal test case and in my actual application (Zulip). Thanks for the quick fix!

[hynek]

Thank you for the quick confirmation!