This is a problem that has been plaguing me for a few months but I haven't taken much time to work out the source of the problem yet.

It might also be dependent on the package version of Cygwin's git pacakge, but when using the system git from Cygwin in a ./sage -sh shell, it's broken. A workaround is to put PATH=/usr/bin:$PATH in front. So it seems maybe some library installed as part of Sage is incompatible with the system git.

This is a problem, in particular, for pip installing packages from a git repo, for example.

Component: porting: Cygwin

Issue created by migration from https://trac.sagemath.org/ticket/25816