Installation mangles existing invoke installation

[andyhasit]

Our CI is failing with an assortment of syntax errors in invoke package. On closer inspection we can see some files in invoke got mangled somehow:

My guess is that magicinvoke install its own copy of invoke (can someone confirm that the case?) - but because poetry installs invoke and magicinvoke in parallel, there is a possibility these two installations partially writing on top of each other.

[andyhasit]

I checked and sure enough, installing magicinvoke REPLACES the source code of your existing invoke installation with its OWN copy of invoke (which is currently frozen at 1.2) but doesn't touch the .dist-info directory, so it appears you have invoke at whatever version you installed, but you actually have 1.2

If anyone runs code which depends on a newer features of invoke, then merely installing magicinvoke would break that.

This is not how Python packages are expected to work, and releasing a library which does something this crazy without a big prominent warning sign stating that you are doing this (and what the consequences are) is pretty irresponsible.

[haydenflinner]

From the README:

as well as including a patched version of invoke with support for *args and **kwargs on tasks, some clearer exceptions, and some minor bugfixes.

If you know another way to do this without replacing the source code, I'm all ears 🙂

[andyhasit]

Hi, thanks for replying. I made a PR with a suggested warning. Unfortunately that will only be read by some people. I wonder if its worth printing some output during installation too.

As for how we implement this without replacing the source code, this may be possible with monkey patching, but it would take a bit of work. And if you do put out a fix, you should inform users they need to reinstall invoke too.

[MaddyGuthridge]

Looks like there isn't a way to declare incompatible dependencies in Python, sadly.