[fpc-pascal] unable to compile 3.0.0 both Linux x86_64 and arm-linux

[Giuliano Colla]

Hello,

I'm trying to upgrade from fpc 2.6.4 to 3.0.0 but make all fails both in 
Linux x86_64 platfoms and in arm-linux (Raspbian) plaform.

I've downloaded a precompiled 3.0.0 in order to be able to compile. I 
have also tried using fpcup, but the result is the same in all cases:

while compiling package paszlib, in file zbase.pas it fails with:

zbase.pas(446,7) Error: Illegal expression

where the offending line is a simple
       str(err,zerror);

and with

zbase.pas(447,36) Error: Operator is not overloaded: "Constant String" + 
"zError(LongInt):AnsiString;"

where the offending line is
     zerror:='Unknown zlib error '+zerror;

If I try to continue by patching the offending lines, the unit compiles 
but then I get tons of errors from the trees.pas unit.

Any idea? Do I need to add some options previously unneeded besides '-gl 
-O3p3' ?

Giuliano