a simple grep reveals this:
grep -nHIirF -- 200411171 (in directory: /home/asta/fpc331/compiler)
./symdef.pas:6999: internalerror(200411171);
./symdef.pas:7006: internalerror(200411171);
Search completed with 2 matches.
Both seem related, but I wonder why there are two! spots with the same internal error. That does not seem correct. (although they are close and cover much the same issue)
Can you detect which of the two is the one you encountered? (I suppose you compile with debug info!)
Note playing with system is asking for trouble. You really need to know what you are doing. (I wrote some of the Delphi system replacements for KOL together with Vladimir Kladov and based on his original. That was not easy and FPC's system unit is even more complex)
Also note the comment at the start of the routine that contains those internal error(s):
procedure tprocdef.setmangledname(const s : TSymStr);
begin
{ This is not allowed anymore, the forward declaration
already needs to create the correct mangledname, no changes
afterwards are allowed (PFV) }
{ Exception: interface definitions in mode macpas, since in that }
{ case no reference to the old name can exist yet (JM) }
Which tells us with this combined info it is macpas related.
Considering the comments, I suggest to ask Jonas Maebe (JM) for help. (best place is on the fp-devel list, not on the forum)