Hi all
This is installing 5.3 for Bionic (18.04) on Focal (20.04) but as I know you’re in the throws of building 5.4 thought I'd throw this out there in case it changes anything;
Installing kamailio from; deb http://deb.kamailio.org/kamailio53 bionic main
The following packages have unmet dependencies: kamailio : Depends: libreadline7 (>= 6.0) but it is not installable kamailio-mysql-modules : Depends: libmysqlclient20 (>= 5.7.11) but it is not installable kamailio-redis-modules : Depends: libhiredis0.13 (>= 0.13.1) but it is not installable
libreadline7 -> libreadline8 (v 8.0-4) libmysqlclient20 -> libmysqlclient21 (v 8.0.21-1ubuntu20.04) libhiredis0.13 -> libhiredis-dev (v 0.14.0-6).
Ubuntu Server 20.04 LTS (focal) MySQL 8 (From MySQL Repo) Redis 6 from latest stable
Best regards Mark