`IndexError` inside `expression_mutation` about mutmut

[boxed]

The first thing to cross my mind is that the crash is handled badly: it should have printed the file, line number (and preferably column) of the parse error. That's bug one. The other problem is probably trivial to understand and turn into a small unit test after that.

If you want to give it a shot the context variable should contain sufficient information for most of that data.

I'll try to look at it as soon as I can but I don't know when that will be.

[boxed]

The dependency tree for poetry plus your project is pretty large I must say. Just installing into a venv is taking a long time!

[boxed]

Well, it was trivial to fix the error output and the bug when I got everything up and running.

I have rolled a new release that fixes your problem. Your test suite is pretty slow, so I would be interested to see if you can have a use for pytest-testmon and if it makes mutation testing faster.

[boxed]

Oh yea, and you might also want to try using the "features" branch of pytest for a while, there are some optimizations there that might be relevant. Or just use 3.6.0 which is the fastest in my measurements.

[sobolevn]

@boxed thanks! Works now. But, yes. That's too slow.

I guess pytest -x --no:flake8 --no:isort --no:cov will make it faster.
Currently measuring the regular execution time.

[sobolevn]

pytest -x -o addopts="" gives an awesome result of 19 seconds per loop.
Thanks again @boxed!