Created attachment 192136 [details]
As noted on http://liballeg.org/ , the allegro library is currently on 5.2.4 and now uses GitHub rather than SourceForge.
I've attached a diff that builds the current latest version.
Created attachment 192138 [details]
Submitted https://reviews.freebsd.org/D15504 to request maintainership and update
Until the review complere, I release this.
Maintainer has been reset in ports r505847.