`pip install vamp-planner` fails due to missing Eigen dependency on M-series Macs

[claytonwramsey]

Note: this is an in-process bug, so I don't have the exact behavior sorted; this is just my compiling the results from a few other labmates.

Describe the bug
When running pip install vamp-planner on an M-series Mac, it fails with the following output:

Expected output

just work!!!

[claytonwramsey]

(The screenshot above was sent to me by a lab member, so I shall attempt to reproduce this on a different machine shortly).

I assume that this is fixable by using e.g. a header version of Eigen3, much like the current WASM builds, to avoid relying on system packages.

[nikkijhart]

This is running in a venv where I have pip installed eigen

[nikkijhart]

Solved with brew install eigen

[Thodoris1999]

After some digging, it seems to be due to this directive here https://github.com/KavrakiLab/vamp/blob/052c8ce2a496b243375e616a2b45df87f91b5242/cmake/Dependencies.cmake#L17 making Eigen a build dependency. vamp-planner PyPI package is a scikit-build built source distribution, which makes Eigen a dependency of pip installing that package as well