Just for reference: Compiling SP on Ubuntu 18.04.5 LTS went smooth following the standard instructions. Only a few of things had to be done apart from this before compiling, nothing much to do with SP itself:
Build osmid (m20/o2m) apart and put it in$SP_HOME/app/server/native/osmid.- Ubuntu 18.04 LTS is slowly getting a little outdated, so Erlang has to be updated to 23 at least, otherwise one gets the
init terminating in do_bootthing from Erlang. I have uninstalled it and then followed these instructions to get the new version. - Update
cmake. I uninstalled the old one and got the new version like so:sudo apt remove cmake sudo snap install cmake --classic
Those were the additional dependencies in my case. I have noticed that my MIDI paths change, but who cares …
Edit: Per @ethancrawford’s remark struck out the osmid part.

although I don’t like snap much either. ppa would probably be better, but I think I’m moving over to 20.04 soon.