Package FTBFS on multiple architectures due to apparent bugs in gcc - how to proceed?

["Zack Weinberg" <zackw@panix.com>]

I maintain a package (monotone) that fails to build from source on
alpha, arm, and ia64 with symptoms that suggest compiler bugs to me.
On arm it's clear-cut: cc1plus segfaults.  On ia64, there are
testsuite failures because exceptions that should have been caught
(and are caught on other architectures) trigger std::terminate.  On
alpha, the primary executable built by the package segfaults on a very
basic operation, causing the entire testsuite to be aborted.  It's
possible that this is a bug somewhere in the package's code, exposed
only on alpha, but I doubt it.

I don't have interactive access to any of the above architectures, and
while I'm happy to provide any information that may be helpful, I have
extremely limited time, especially for the next few weeks.  In
particular I cannot provide minimized test cases of the sort that
upstream GCC would want to see.  The build logs at
http://buildd.debian.org/~jeroen/status/package.php?p=monotone are all
the information I currently have about these failures.  [Ignore mips
and mipsel, those build failures have an entirely different cause
which is not a compiler problem.]

Given all of the above, what do you (GCC maintainers) think would be
the most efficient way to get these bugs diagnosed and fixed?

Thanks,
zw