I need to build XFree86 for sparc32, natively via make World. Since my
   only 32bit SPARC is rather slow I'd like to do it on my U10, in a
   chrooted 32bit userland. Are there any pitfalls to watch out for? I know
   gcc likes to do funny things to the vm subsystem - will this work
   properly with COMPAT_NETBSD32?


what do you mean about gcc?  i have no idea what you are talking
about at all.  the biggest problem i can imagine is that xsrc will
attempt to build for sparc64 because uname -m = sparc64 (though this
is changing soon/has changed lately?)


another problem i'd expect is the now large number of system calls
not handled by compat_netbsd32.  cube@ has been working on a few of
them, but entire groups like the sa_* (pthreads) calls are not yet
handled.  another likely problem would be random bugs in various
emulated syscalls.