If Coro causes segfaults a lot on calls to libc functions, the cause is
probably a glibc compiled for i386 and kernel 2.2.

Glibc contains a bug that causes any program linked against pthreads AND
using coroutines (of any kind, not only Coro, but including most userspace
thread libraries like gnu-pth) or alternate stacks to segfault on calls to
pthread functions. And glibc happens to do a lot of these calls.

(Even if you pelr is not compiled against pthreads, Time::HiRes links
against -lrt, which drags in pthreads. The same is true for other modules,
so watch out).

The bug is rather difficult to fix. This is not a problem, however, since
glibcs compiled for linux-2.4 use a much more efficient method to locate
their data, which happens to work with coroutines.

So the easy fix is to install a libc which was compiled for linux-2.4,
using the "--enable-kernel=2.4 i586-pc-linux-gnu" configure options.

WARNING: This libc will no longer run on linux-2.2 or lower!

UPDATE: I am no longer able to compile glibc-2.3.2 in this way. The reason
is most probably that the glibc folks work on an enhanced thread local
storage facility, and it might be that you need a 2.5 or 2.6 kernel to
make it work.  Glibc-2.3.1 works fine, though.