bug#42372: python-tinycss2 fails to build

[Michael Rohleder]

Hey guix,

I tried building weasyprint, but python-tinycss2 fails in (flake?)
tests:

...
starting phase `check'
============================= test session starts ==============================
platform linux -- Python 3.8.2, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
rootdir: /tmp/guix-build-python-tinycss2-1.0.2.drv-0/tinycss2-1.0.2, inifile: 
setup.cfg
plugins: hypothesis-5.4.1, flake8-1.0.6, isort-0.3.1
collected 498 items

setup.py ..                                                              [  0%]
tinycss2/__init__.py ..                                                  [  0%]
tinycss2/ast.py ..                                                       [  1%]
tinycss2/bytes.py ..                                                     [  1%]
tinycss2/color3.py ..                                                    [  2%]
tinycss2/nth.py ..                                                       [  2%]
tinycss2/parser.py ..                                                    [  2%]
tinycss2/serializer.py ..                                                [  3%]
tinycss2/test_tinycss2.py .............................................. [ 12%]
........................................................................ [ 26%]
........................................................................ [ 41%]
........................................................................ [ 55%]
........................................................................ [ 70%]
........................................................................ [ 84%]
......................................................................   [ 98%]
tinycss2/tokenizer.py ..                                                 [ 99%]
tinycss2/css-parsing-tests/make_color3_hsl.py .F                         [ 99%]
tinycss2/css-parsing-tests/make_color3_keywords.py ..                    [100%]

=================================== FAILURES ===================================
_________________________________ FLAKE8-check _________________________________
/tmp/guix-build-python-tinycss2-1.0.2.drv-0/tinycss2-1.0.2/tinycss2/css-parsing-tests/make_color3_hsl.py:19:9:
 E741 ambiguous variable name 'l'

------------------------------ Captured log call -------------------------------
WARNING  flake8.options.manager:manager.py:207 option --max-complexity: please 
update from optparse string `type=` to argparse callable `type=` -- this will 
be an error in the future
======================== 1 failed, 497 passed in 2.63s =========================
command "pytest" failed with status 1
builder for 
`/gnu/store/29xnjbi81x88w5pc8rkj09ffcr62y0z5-python-tinycss2-1.0.2.drv' failed 
with exit code 1
build of /gnu/store/29xnjbi81x88w5pc8rkj09ffcr62y0z5-python-tinycss2-1.0.2.drv 
failed


-- 
If you are the smartest person in the room,
you are in the wrong room.