When x86-64 switched on NPTL in uClibc, distcc broke, and it turns out fully native compiles under qemu never worked due to qemu not quite emulating floating point right and confusing the perl build with zero not comparing equal to zero. As long as it's broken anyway, switch it over to musl and fix it up on that side. It's no longer worth trying to fix anything broken in uClibc, the project is dead. (I'm aware of uClibc-ng, and am treating it exactly the same way I treated the ecommstation reboot of OS/2.)

--- gcc-g++/libstdc++-v3/configure	2007-01-29 04:51:01.000000000 -0600
+++ gcc-g++2/libstdc++-v3/configure	2008-11-02 03:46:15.000000000 -0600
@@ -7947,7 +7947,7 @@
 
   echo "$as_me:$LINENO: checking for thread model used by GCC" >&5
 echo $ECHO_N "checking for thread model used by GCC... $ECHO_C" >&6
-  target_thread_file=`$CXX -v 2>&1 | sed -n 's/^Thread model: //p'`
+  target_thread_file=posix
   echo "$as_me:$LINENO: result: $target_thread_file" >&5
 echo "${ECHO_T}$target_thread_file" >&6