I thought today was going to be a good day. I was going to release the first alpha version of coverage.py 4.0. I finally finished the support for gevent and other concurrency libraries like it, and I wanted to get the code out for people to try it.

So I made the kits and pushed them to PyPI. I used to not do that, because people would get the betas by accident. But pip now understands about pre-releases and real releases, and won’t install an alpha version by default. Only if you explicitly use --pre will you get an alpha.

About 10 minutes after I pushed the kits, someone I was chatting with on IRC said, “Did you just release a new version of coverage?” Turns out his Travis build was failing.

He was using coveralls to report his coverage statistics, and it was failing. Turns out coveralls uses internals from coverage.py to do its work, and I’ve made big refactorings to the internals, so their code was broken. But how did the alpha get installed in the first place?

He was using tox, and it turns out that when tox installs dependencies, it defaults to using the --pre switch! Why? I don’t know.

OK, I figured I would just hide the new version on PyPI. That way, if people wanted to try it, they could use “pip install coverage==4.0a1”, and no one else would be bothered with it. Nope: pip will find the newer version even if it is hidden on PyPI. Why? I don’t know.

In my opinion:

• Coveralls shouldn’t have used coverage.py internals.
• Tox shouldn’t use the --pre switch by default.
• Pip shouldn’t install hidden versions when there is no version information specified.

So now the kit is removed entirely from PyPI while I figure out a new approach. Some possibilities, none of them great:

1. Distribute the kit the way I used to, with a download on my site. This sucks because I don’t know if there’s a way to do this so that pip will find it, and I don’t know if it can handle pre-built binary kits like that.
2. Do whatever I need to do to coverage.py so that coveralls will continue to work. This sucks because I don’t know how much I will have to add back, and I don’t want to establish a precedent, and it doesn’t solve the problem that people really don’t expect to be using alphas of their testing tools on Travis.
3. Make a new package on PyPI: coverage-prerelease, and instruct people to install from there. This sucks because tools like coveralls won’t refer to it, so either you can’t ever use it with coveralls, or if you install it alongside, then you have two versions of coverage fighting with each other? I think?
4. Make a pull request against coveralls to fix their use of the now-missing coverage.py internals. This sucks (but not much) because I don’t want to have to understand their code, and I don’t have a simple way to run it, and I wish they had tried to stick to supported methods in the first place.
5. Leave it broken, and let people fix it by overriding their tox.ini settings to not use --pre, or wait until people complain to coveralls and they fix their code. This sucks because there will be lots of people with broken builds.

Software is hard, yo.