Guidance requested on narrowing down internal compiler error

[john o goyo]

Greetings, Gaius.

Compiling a legacy module gave me the following error.

cc1gm2: internal compiler error: not implemented yet
0x6d267f m2linemap_internal_error
/home/build/opt/gcc/src/gcc-git/gcc/m2/gm2-gcc/m2linemap.cc:253
[...]
0x772a9b Type
        m2/gm2-compiler-boot/P2Build.c:4179
0x775293 Definition
        m2/gm2-compiler-boot/P2Build.c:7145
Please submit a full bug report, with preprocessed source (by using 
-freport-bug).

The problem is that no line number is reported.  Is there a gm2 option 
that allows me to narrow it done?  (The module is 300 lines long.)

Sincerely,
john