Developer install does not work

[rainman110]

Installing via python setup.py install works.

But installing via pip install -e . does not. This is however the preferred way for the development cycle.

[d1saster]

Just adding PEP 660 for future reference here. So far I don't know how to make this work together with PEP 517 and 518.

[d1saster]

As it turns out PEP660 was implemented by setuptools in pypa/setuptools#3488 (part of the 64.0.0 release, which happened on Aug 11, 2022, so quite fresh) which according to my testing fixes this bug.

Since there are currently only few developers and the editable build is not the standard build, I feel reluctant to add setuptools>=64.0.0 as a build requirement to pyproject.toml. Note that the issue can persist im you (very likely still) have an older version of setuptools in your pip cache. It is best to check with increased verbosity which version of setuptools is used for building mpi4torch, i.e. using pip install -v -e . when installing from a local checkout.

[d1saster]

And pip of course needs also to be younger than 21.3 to have PEP660 support.