Building macOS installer fails

[carlosperate]

pup throws the following error:

I dmgbuild err: Traceback (most recent call last):
I dmgbuild err:   File "/Users/carlos/workspace/carlos/mu/venv-pup/bin/dmgbuild", line 5, in <module>
I dmgbuild err:     from dmgbuild.__main__ import main
I dmgbuild err:   File "/Users/carlos/workspace/carlos/mu/venv-pup/lib/python3.7/site-packages/dmgbuild/__init__.py", line 1, in <module>
I dmgbuild err:     from .core import build_dmg
I dmgbuild err:   File "/Users/carlos/workspace/carlos/mu/venv-pup/lib/python3.7/site-packages/dmgbuild/core.py", line 42, in <module>
I dmgbuild err:     from mac_alias import *
I dmgbuild err: AttributeError: module 'mac_alias' has no attribute 'kBookmarkVolumePathkBookmarkVolumeURL'
E [Errno 2] No such file or directory: '/Users/carlos/workspace/carlos/mu/build/pup/Mu Editor.dmgbuild/Mu Editor 1.2.0.dmg'
I Step 'mac.create-dmg': completed.

This comes from the mac_alias package, which is installed as a depedency of dmgbuild, which is a depedency of pup.

The issue is already identified, and a PR raised, but it hasn't been merged and released yet:

• Broken imports from mac_alias in 2.2.1 dmgbuild/mac_alias#21
• Fix "AttributeError: module 'mac_alias' has no attribute 'kBookmarkVolumePathkBookmarkVolumeURL'" dmgbuild/mac_alias#20

Possible workarounds right now:
a. Update pup to pin mac_alias==2.2.0
b. Install mac_alias==2.2.0 in the pup virtual env, before installing pup

Option a) might take a little while, as Tiago is likely busy at the moment and might not have the bandwidth to do a release soon (@tmontes tagging you for visibility, but no need to look into this right now).

I'll prepare a PR for option b), which we can remove when the next version of mac_alias is released.

[carlosperate]

I've merge PR #2366 with a temporary workaround, and responded to the mac_alias issue to keep an eye on the resolution. So I'll leave this issue open as a reminder to remove the workaround once there is a new mac_alias release.

[carlosperate]

The mac-alias pup dependency was updated and the workaround has been removed 🎉