MacPython/pandas-wheels wheel builds failing

[TomAugspurger]

This affects the linux builds, both py37 and py38, 32 or 64-bit.

https://dev.azure.com/pandas-dev/pandas-wheels/_build/results?buildId=30996&view=logs&j=517fe804-fa30-5dc2-1413-330699242c05&t=2e128ad5-2f7f-5333-3f34-c85b8fbc7250&l=1216

=================================== FAILURES ===================================
__________________________ test_no_permission[c_high] __________________________
[gw1] linux -- Python 3.7.0 /venv/bin/python

            with pytest.raises(PermissionError, match=msg) as e:
>               parser.read_csv(path)

/venv/lib/python3.7/site-packages/pandas/tests/io/parser/test_common.py:978: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/venv/lib/python3.7/site-packages/pandas/tests/io/parser/conftest.py:22: in read_csv
    return read_csv(*args, **kwargs)
/venv/lib/python3.7/site-packages/pandas/io/parsers.py:676: in parser_f
    return _read(filepath_or_buffer, kwds)
/venv/lib/python3.7/site-packages/pandas/io/parsers.py:449: in _read
    parser = TextFileReader(fp_or_buf, **kwds)
/venv/lib/python3.7/site-packages/pandas/io/parsers.py:880: in __init__
    self._make_engine(self.engine)
/venv/lib/python3.7/site-packages/pandas/io/parsers.py:1112: in _make_engine
    self._engine = CParserWrapper(self.f, **self.options)
/venv/lib/python3.7/site-packages/pandas/io/parsers.py:1935: in __init__
    self._reader = parsers.TextReader(src, **kwds)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   pandas.errors.EmptyDataError: No columns to parse from file

pandas/_libs/parsers.pyx:532: EmptyDataError

Looks to be from #32839

cc @gfyoung @roberthdevries

[roberthdevries]

Nope it's from #32737

[roberthdevries]

The test makes the file unreadable by doing chmod(path, 0). This means nobody is allowed to read it. But for some reason, this does not work on all platforms. Originally this only did not work for Windows. But now apparently it also does not work on Azure.
The EmptyDataError exception is caused by the fact that the file is actually empty. There is no need to fill a file that you cannot read.

[TomAugspurger]

What needs to change? Something in the test?

[roberthdevries]

My guess is the test environment. But I don't understand why setting the mode of the file fails. This is a regular Linux OS, is it? Or is Azure doing something special here?

[roberthdevries]

Is this pipeline by any chance running as root?

[TomAugspurger]

I'm not sure. I don't see anything in the logs about what the user is.