I'm using the Win10 built-in linux system and type pip install -U .
and then I got a terrible error:
ERROR: Could not install packages due to an OSError: [('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/branches', '/tmp/pip-req-build-luuzar9x/.git/branches', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/branches'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/hooks', '/tmp/pip-req-build-luuzar9x/.git/hooks', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/hooks'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/info', '/tmp/pip-req-build-luuzar9x/.git/info', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/info'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/logs/refs/heads', '/tmp/pip-req-build-luuzar9x/.git/logs/refs/heads', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/logs/refs/heads'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/logs/refs/remotes/origin', '/tmp/pip-req-build-luuzar9x/.git/logs/refs/remotes/origin', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/logs/refs/remotes/origin'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/logs/refs/remotes', '/tmp/pip-req-build-luuzar9x/.git/logs/refs/remotes', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/logs/refs/remotes'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/logs/refs', '/tmp/pip-req-build-luuzar9x/.git/logs/refs', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/logs/refs'"), ('/mnt/f/MyDownloads/Download/cactus-bin-v1.2.3/.git/logs', '/tmp/pip-req-build-luuzar9x/.git/logs', "[Errno 22] Invalid argument: '/tmp/pip-req-build-luuzar9x/.git/logs'"),
I use python3.6 and the built-in linux system is just called out. I really don't know why I got such an error.