Bug Report

[julie77793@gmail.com]

Cygwin doesn't create an environment variable in bash to indicate that the
platform is Cygwin under Windows.

This causes compatibility problems when running various tools. Most of my
issues have been with Python tools running Windows Python.

I have been addressing this issue by grepping PATH for cygdrive which
doesn't seem like a very good approach.

Both msys2 and mingw solve this issue by setting the MSYSTEM environment
variable which lets tools check that OS=Windows_NT and MSYSTEM=MSYS

Please add some way of identifying that programs are running under Cygwin.