With the new -print-file-name option for pcc, I've managed to get musl's configure to recognize pcc. (See pcc-configure.diff)
But I've run into one other problem: when 
-mtune=generic -march=486
is passed to pcc in the linking stage, it appears that pcc passes some invalid option to ld (I get "Unrecognized option: tune=generic", as shown at the very end of make.pcc).
Should the -m... options be omitted from what pcc passes to ld?

Additionally, if I work around that, I get a segfault when running hello world (via .../lib/libc.so a.out):
(gdb output)
program received signal SIGSEGV, Segmentation fault.
0x755b91d9 in __syscall_cp ()
(gdb) where
#0  0x755b91d9 in __syscall_cp ()
#1  0x7557268a in open64 ()
#2  0x755779ad in __dynlink ()
#3  0x7557858d in _start ()
I'll try rebuilding with -O0 -g3.
(Rich: in case you're wondering, -Bsymbolic-functions is being properly passed)

Thanks,
Isaac Dunham <idunham@lavabit.com>