Well, with a default install there are no revision numbers...except 3.0.2, 3.0.4 etc.
But you can add them for trunk yourself.
Example:
sudo make clean all install REVSTR=36912 REVINC=force INSTALL_PREFIX=/usr/local/ OPT='-dREVINC -CpARMv7a -CfVFPv4 -OoFASTMATH -OpARMv7a -Fl/usr/lib/gcc/arm-linux-gnueabihf/4.9.2 -vm5024' GDBMI=1
After that built you will get a nice:
Free Pascal Compiler version 3.1.1-r36912 [2017/08/15] for arm
Copyright (c) 1993-2017 by Florian Klaempfl and others
/usr/local/bin/fpc [options] <inputfile> [options]
Only options valid for the default or selected platform are listed.
So you will have to do it by hand or write a script.
The revision 36912 is what the svn checkout gives you in this case...
It is not for noobs. If you can't even build from source, don't use it.
Trunk is for freaks, debuggers and developers, not for programmers..