[4.6] Improve output when parsing an ini configuration fails (#5650)

[nicoddemus]

Backport of #5650

[nicoddemus]

@RonnyPfannschmidt, any hints why setuptools-scm is producing pytest-0.1.dev57+g28ddc62?

.package create: /home/travis/build/pytest-dev/pytest/.tox/.package
.package installdeps: setuptools>=40.0, setuptools-scm, wheel
py36-xdist create: /home/travis/build/pytest-dev/pytest/.tox/py36-xdist
py36-xdist installdeps: pytest-xdist>=1.13
py36-xdist inst: /home/travis/build/pytest-dev/pytest/.tox/.tmp/package/1/pytest-0.1.dev57+g28ddc62.tar.gz
py36-xdist installed: apipkg==1.5,argcomplete==1.10.0,atomicwrites==1.3.0,attrs==19.1.0,certifi==2019.6.16,chardet==3.0.4,execnet==1.6.1,hypothesis==4.32.2,idna==2.8,importlib-metadata==0.19,more-itertools==7.2.0,nose==1.3.7,packaging==19.1,pluggy==0.12.0,py==1.8.0,pyparsing==2.4.2,pytest==0.1.dev57+g28ddc62,pytest-forked==1.0.2,pytest-xdist==1.29.0,requests==2.22.0,six==1.12.0,urllib3==1.25.3,wcwidth==0.1.7,zipp==0.5.2

[asottile]

the failure here is weird, did travis not fetch tags properly (or are there too many commits for setuptools-scm to find a closest?)

[blueyed]

Related: pypa/setuptools-scm@2555a9f (but not released) - shows what it does though.

[RonnyPfannschmidt]

@nicoddemus i vaugely recall travis adds only about 50 commits by default, which is a problem in some cases like this one

[RonnyPfannschmidt]

https://travis-ci.org/pytest-dev/pytest/jobs/562618711#L160 <- depth of 50 - its lacking, i recall that travis has no describe equivalent so we are in a blind here

[RonnyPfannschmidt]

@nicoddemus i believe setting https://docs.travis-ci.com/user/customizing-the-build/#git-clone-depth will help

[codecov]

Codecov Report

Merging #5652 into 4.6-maintenance will increase coverage by 0.28%.
The diff coverage is 100%.

@@                 Coverage Diff                 @@
##           4.6-maintenance    #5652      +/-   ##
===================================================
+ Coverage            95.91%   96.19%   +0.28%     
===================================================
  Files                  115      115              
  Lines                26504    26512       +8     
  Branches              2613     2613              
===================================================
+ Hits                 25420    25502      +82     
+ Misses                 757      704      -53     
+ Partials               327      306      -21

Impacted Files	Coverage Δ
src/_pytest/config/findpaths.py	95.14% <100%> (+1.14%)	⬆️
testing/test_config.py	99.83% <100%> (+0.33%)	⬆️
src/_pytest/fixtures.py	97.55% <0%> (+0.27%)	⬆️
testing/test_capture.py	99.25% <0%> (+0.29%)	⬆️
testing/test_terminal.py	99.84% <0%> (+0.31%)	⬆️
testing/test_pdb.py	99.22% <0%> (+0.38%)	⬆️
src/_pytest/pytester.py	91.66% <0%> (+0.42%)	⬆️
src/_pytest/assertion/rewrite.py	95.77% <0%> (+0.48%)	⬆️
testing/python/fixtures.py	99.09% <0%> (+0.56%)	⬆️
... and 13 more

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[nicoddemus]

Done, if that works, we should cherry-pick it to master.

[nicoddemus]

SIGH

[asottile]

that's pretty unfortunate :/

though, I wonder the trade off on how much time shallow cloning saves vs the features setuptools-scm gives us (I'm not familiar with them enough to make a call here)

[nicoddemus]

How much time does shallow cloning saves us?

setuptools-scm helps us with have a new version automatically just by pushing a tag, which I enjoy immensely.

[blueyed]

You could still limit it to 1000.
The default is 50.
Having additional merge commits for single commit changes (or even 5+ "updated X" commits for what should be a single commit, because you cannot easily squash-merge certainly does not help here ;))

But to be fair: for a stable branch it is easy to get away 50+ commits anyway.

[blueyed]

setuptools-scm helps us with have a new version automatically just by pushing a tag, which I enjoy immensely.

FWIW I find https://github.com/zsimic/setupmeta/ to be even greater (with the same limitations here probably though).