On Windows, with Cygwin-git 02.12.2-1 the python command: pip install git+https://github.com/...` fails to work with the following error: $ pip install git+https://github.com/ipython/traitlets/ Collecting git+https://github.com/ipython/traitlets/ Cloning https://github.com/ipython/traitlets/ to c:\users\username\appdata \local\temp\pip-kjwxq_oy-build fatal: Invalid path '/cygdrive/d/Work/ALLINONES2/co2mpas_AIO-v1.6.0/CO2MPA S/C:\Users\username\AppData\Local\Temp\pip-kjwxq_oy-build': No such file or di rectory git clone -q https://github.com/ipython/traitlets/ C:\Users\user\AppData\L ocal\Temp\pip-kjwxq_oy-build" failed with error code 128 in None Git-2.8.3 had no such problem. Any ideas?