python: docker: build failure on Darwin

[smaret]

Describe the bug

python37Packages.docker fails to build on Darwin with the following error message:

builder for '/nix/store/320aynm8i2bnks3ijcyhv69x6k9bcvbf-python3.7-docker-4.1.0.drv' failed with exit code 1; last 10 log lines:
          self.addCleanup(shutil.rmtree, base)
          for d in ['foo', 'bar']:
              os.makedirs(os.path.join(base, d))
          sock = socket.socket(socket.AF_UNIX)
          self.addCleanup(sock.close)
  >       sock.bind(os.path.join(base, 'test.sock'))
  E       OSError: AF_UNIX path too long

To Reproduce

1. nix build --option build-use-sandbox true -I . nixpkgs.python37Packages.docker

Metadata

• system: "x86_64-darwin"
• host os: Darwin 19.0.0, macOS 10.15.1
• multi-user?: no
• sandbox: no
• version: nix-env (Nix) 2.3.1
• channels(smaret): "nixpkgs-19.03pre170546.0f43790d2ce"
• nixpkgs: /nix/store/kd1bflipda7jjnfqxjfiym9268akzq2c-master.tar.gz

cc @jonringer

[jonringer]

unfortunately the sandbox environment does create really long paths, too long for darwin to handle by default, I'll disable the affected tests

[marsam]

you could backport #72002; however I recommend you to upgrade to 19.09, because 19.03 has reached end of support:

End of support is planned for end of October 2019, handing over to 19.09.
https://nixos.org/nixos/manual/release-notes.html#sec-release-19.03-highlights

[smaret]

@marsam I'm using the HEAD version of nixpkgs from Github, not the 19.03 channel (not sure why nix-info says that I'm using 19.03). It's a different issue than the one you fixed with #72002.