UPDATE: the problem only affects the x11/ subcomponent, since I reached a successful build by editing by hand
x11/Makefile
adding -lpthread to LIBS, and then restarting the build from the top source directory.
The build of the crossfire-client-1.12.0 breaks for me under Slackware 12.2 /x86-32
I think that's a missing linking option for pthread.
Attached the full console.log with all commands run and stdout/stderr.
The following is standard error only:
mapdata.c: In function 'mapdata_set_anim_layer':
mapdata.c:805: warning: 'speed_left' may be used uninitialized in this function...
