[Lazarus] How to use two different versions of FPC

[Gabor Boros]

Hi All,

My main development toolset is FPC 3.0.4 and Lazarus fixes_1_8. 
Sometimes I try some things with Lazarus trunk also. It is easy.
But now build up a new development machine from scratch with RHEL 7.5 on 
it and try to utilize FPC trunk too (with Lazarus trunk). I use 
"--primary-config-path" option always, so Lazarus config placement is 
not a problem. But the two FPC versions coexist. I found a solution from 
2012 on the forum (see the link below). Is BigChimp's suggestion (1.-6.) 
a good starting point nowadays or something changed meanwhile in this 
topic. I will build everything (Lazarus fixes_1_8 and trunk, FPC trunk) 
from source except the actual stable FPC (now 3.0.4).

https://forum.lazarus.freepascal.org/index.php/topic,15716.msg85158.html#msg85158

Gabor