I think I may be the only person for whom this is relevant, but if you’re running from source on FreeBSD, beware of the latest elixir packages in FreeBSD 14.1, updated this week. I’d previously been using the elixir-devel package in order to meet Akkoma’s minimum version requirements. This week’s updates are version upgrades for both the mainline elixir package (now 1.16) and elixir-devel (now 1.17), and my Akkoma server wouldn’t run after the package upgrade.
The system erlang package is currently version 25.3. The elixir-devel package says it needs erlang-runtime27 or newer, but something about that wouldn’t work with the system erlang. The first working configuration I could find was to have the system erlang (25.x), the erlang-runtime25 package, and the mainline elixir package instead of elixir-devel. Once those were installed it was just the usual set of mix commands to rebuild the same source release with the new environment.