(re)-introduce exit codes

[waltervos]

I'm looking to integrate mutmut in our CI pipelines, and I'm looking for a good way to detect mutmut's result to determine whether to fail the pipeline or not.

It looks like mutmut run used to have several possible exit codes (from #67 and #49) but they seem to have been dropped from the code base.

What is the current recommendation on integrating mutmut into a CI pipeline?

[boxed]

I keep telling people it's a bad idea and people keep telling me they want to do it 😜

I am willing to accept PRs for it though.

[waltervos]

Now I'm interested to know why it's a bad idea... Would you recommend running mutation tests as part of a CI pipeline at all? If so, how? And if not, could you elaborate on that? :-)

[boxed]

#270 (comment)

I have written about it in many issues over the years, but this one was the first I found when searching.