[lazarus] How do I compile a form

[rob young]

When I compile a very basic program is works Lazarus works fine. When I 
add a form I get the following error at the end of this email.

(I am compiling in Linux) 
/home/rob/lazarus/lazarus/lcl/interfaces/gtk/interfaces.pp

was added to my project in this case, but the compiler does not seem to 
be able to find it.
I also added 
/home/rob/lazarus/lazarus/lcl/interfaces/gtk/
to my Libraries but the compiler still does not seem to find the 
interfaces.pp

I was looking through the mailing list but did find any thing there to 
help me.

This seems like a simple task is there there a tutorial or some 
documentation I can look at?

[TCompiler.Compile] CmdLine="/usr/bin/ppc386 -B  -Rintel -S2cgi 
-Ch8000000 -Og1p1 -g1 -XD -vewnhi -l 
/home/rob/lazarus/lazarus/test/project1.pas"
.
.
.
[TCompiler.Compile] Output="lcllinux.pp(8,27) Fatal: Can't find unit 
INTERFACES"
[TCompiler.Compile] end