Because of issue https://www.redmine.org/issues/28725 current Redmine port version 3.4.5 can't work with current Mercurial port version 4.6. This issue is fixed in Redmine 3.4.6 Bugfix: update redmine to 3.4.6 or newer
If no one updates it whenever I get home tonight I will try working on updating this
Scratch that will work on updating when I’m on my lunch break
So far the newest redmine builds on 10.4 waiting on build for 11.2. If it builds fine I’ll upload patch to bugs to get it updated as soon as possible
Patch has been provided in a separate issue (bug 229813). This issue can be closed when that issue is closed (and the patch has landed).
(In reply to Kubilay Kocak from comment #4) 3.4.6 is now in ports tree
Fixed in ports r476463