This is experimental and currently under development. It currently builds cleanly under Debian Wheezy (LP64), however there are a number of restrictions which are currently being worked upon. These include:
University of ULM libraries are disabled.
Arithmetic using complex data types cause the compiler to crash.
The internals of GNU Modula-2 have been heavily overhauled, in particular the code interfacing the Modula-2 front end and the interface to the construction of GCC Trees. This should mean that maintenance is easier in the future and it should reduce the time to graft gm2 onto future gcc releases. In addition, the changes will allow for integer overflow to be detected.