nixos/redmine mercurial integration is broken

[Stekke]

Describe the bug
Browsing a hg (mercurial) repository in a redmine project does not work. No repo functionality works when hg is used.

To Reproduce
Steps to reproduce the behavior:

1. Make use of the redmine module
2. Add a local hg repo to which redmine has access.
3. In redmine, go to the project settings page and add the local hg repo
4. Click the added repo name, or click on the "repository" tab of the project

Now you get to see a 404 page.

Expected behavior
Normally you should be able to browse the repository.

Logs
This issue happens both in the current nixos release and in the unstable, but with different errors:
In release 20.03

Aug 08 18:07:33 nixos bundle[871]: *** failed to import extension redminehelper from /nix/store/c2za42x86iqk8wrxphl4pc2rkb5kbwxq-redmine-4.1.1/share/redmine/lib/redmine/scm/adapters/mercurial/redminehelper.py: unicode 'rhannotate' found in cmdtable
Aug 08 18:07:33 nixos bundle[871]: *** (use b'' to make it byte string)
Aug 08 18:07:33 nixos bundle[871]: hg: unknown command 'rhsummary'
Aug 08 18:07:33 nixos bundle[871]: (did you mean summary?)

In unstable

Aug 08 18:30:38 nixos bundle[1133]: *** failed to import extension redminehelper from /nix/store/3sdqxliq5qd15wfzyiclqs5ax1b6ggnc-redmine-4.1.1/share/redmine/lib/redmine/scm/adapters/mercurial/redminehelper.py: module 'cgi' has no attribute 'escape'
Aug 08 18:30:38 nixos bundle[1133]: hg: unknown command 'rhsummary'
Aug 08 18:30:38 nixos bundle[1133]: (did you mean summary?)

Additional context
The python hg script that is shipped with redmine (redminehelper.py) seems to be incompatible with the python version is being used when it is called.
Possible related upstream bug: https://www.redmine.org/issues/33784

Notify maintainers
@aanderse

[aanderse]

I've never used hg so wouldn't know where to start. Can you provide some config that I can reproduce this with and maybe something will occur to me?

[Stekke]

Not sure what I can give in terms of config.
In order to reproduce you basically do the same as you would with git:

mkdir repo
cd repo/
hg init
touch testfile
hg add testfile
hg commit -m"Added testfile"

And then add it as a repository in the redmine project config, like so:

EDIT: Not sure if the path should or shoudn't include the .hg at the end, but I didn't get it to work either way.

If you then click on the repo link "hg", or on "repository" tab of the project you get:

I then checked what the error log was with: journalctl -u redmine

The following archive has the /var/lib/redmine state directory + also the repo directory as described above + redmine_mysql.db , a database dump of the redmine mysql database (login: admin, password: testtest)
redmine.tar.gz

To be honest I'm not sure if this can be solved in NixOS at all. We might just have to wait until compatibility with python3 is improved upstream.

[prusnak]

Sounds like an upstream bug - have you tried reporting it upstream?

[Stekke]

I think it's already reported: https://www.redmine.org/issues/33784
But I'll add a comment there linking back here...
The patch posted there might solve the issue for us.

[Stekke]

I created a draft PR for this, which I verified fixes this issue.
Though I don't know if we really want to carry around a patch ourselves until upstream fixes things...
The current mercurial <-> redmine situation can't really get any worse, and I don't think this patch can break anything else.
But it might also be worth it to wait for a proper fix from upstream.

[prusnak]

I think's fine to carry a patch until upstream fixes things if these two things are met:

• upstream is already aware of the patch - done
• our patch contains reference to the upstream bug report - not done, left you a suggestion in the PR - see nixos/redmine: patch mercurial integration #94999 (comment)