Custom develop command to link data files in setup.py

[jtpio]

We can add a custom develop command to the setup.py to automatically link data files, as mentioned in #253 (comment).

This would help with the development workflow and make the process more automated.

[vidartf]

Please note that the solution linked will break the -e install command on Windows due to CPython's poor symlink support on Windows. At the very least, please put the symlink call in a try/except clause :)

[jtpio]

Ah good to know :)

Maybe there is a better way to do it so it's more robust on Windows?

[vidartf]

I have one PR on Windows symlink support for CPython that was merged, and one that is still open. If you put the symlink call in a try/except clause, with the current behavior as fallback, that is likely the best way. Then, the symlinking should just work once CPython gets better support.

[maartenbreddels]

Could you link to the PR @vidartf ?
Will this be backported to Python3.6/3.7?

[vidartf]

Will this be backported to Python3.6/3.7

No, I cannot believe it will (unless I have misunderstood how CPython works). I don't think it will be backported to 3.8 either, and given the speed things are going, I doubt it will be in for 3.9...

[vidartf]

Either way, it won't work on all Windows machines, so the try/except clause would still be needed no matter what.

[maartenbreddels]

What should we do instead, give a warning saying you should run it in admin mode? And if not possible (user cannot have admin right), what should a user do, just do a normal pip install .?

[vidartf]

You could just make a helper script (possibly an entry point) that does the copy for you, and ask the user to run that when the datafiles change.

[maartenbreddels]

Why not rerun pip install .? Would that be too slow?

[vidartf]

Sure, you could tell the user to:

• Either configure the symlinks themselves outside of Python (maybe list dirs that need to be linked).
• Or run pip install . for every change to the datafiles (preferably specifying what will trigger a change of theses)

[jtpio]

Closing as this was implemented as a hatch plugin in #1197.