How to build a package with an option?

[fengwang]

I would like to build dvc with option azure. Using pip3, I can install it by executing pip3 install 'dvc[azure]', but using pypi2pkgbuild: pypi2pkgbuild.py -v 'dvc[azure]', I got such error message

$ pypi2pkgbuild.py -v  'dvc[azure]'         
DEBUG:pypi2pkgbuild:This is pypi2pkgbuild 0.3.post2+gdbdb652.
DEBUG:pypi2pkgbuild:Running subprocess:
pkgfile pkgfile >/dev/null
ERROR:pypi2pkgbuild:Package dvc[azure] not found.

[anntzer]

This was not supported due to pypa/pip#3797 (and the limitation (or rather a similar one) is noted in https://github.com/anntzer/pypi2pkgbuild/blob/main/TODO.rst#issues); I guess I could consider a PR that fixes that.