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) or alternate stacks to
segfault on calls to pthread functions. And glibc happens to do a lot of
these calls.

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 tiwh coroutines.

So the easy fix is to install a libc which was compiled for linux-2.4,
using the --enable-kernel=2.4 configure option. WARNING: This kernel will
no longer run on linux-2.2 or lower!