Python offlineDistutils and purity

[cillianderoiste]

I noticed that python packages are still downloading and installing dependencies from pypi (when not building with chroot). Perhaps I am just confused by what happened with the python-rework merge. I expected that allow_hosts = None would now be the default (to stop easy_install downloading packages), and that the --no-deps option would be used for the special cases where there are circular dependencies, via offlineDistutils.

@chaoflow do you remember the details?

I guess we just would need to adjust the installCommand in offlineDistutils to add --no-deps, and move the distutils.cfg stuff to the generic expression where we can also add zip_safe = 0, #270.

Changing the global distutils.cfg will cause a massive rebuild so we'd need another test cycle.

[chaoflow]

@cillianderoiste: exactly, offlineDistutils is used and should work. '--no-deps' is only used for individual packages that need to work around circular dependencies.

[chaoflow]

This indeed happily downloads:

NIX_REMOTE= sudo nix-build -A ...