This can't be good: gcc -g -o sbcl.exe alloc.o backtrace.o breakpoint.o coreparse.o dynbind.o funcal l.o gc-common.o globals.o interr.o interrupt.o largefile.o monitor.o os-common.o parse.o print.o purify.o pthread-futex.o pthread-lutex.o regnames.o run-program .o runtime.o save.o search.o thread.o time.o util.o validate.o vars.o wrap.o x86 -arch.o win32-os.o x86-win32-os.o gencgc.o x86-assem.o -mno-cygwin -lm interrupt.o: In function `deferrables_blocked_p': /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:256: undefined refere nce to `_deferrable_sigset' /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:256: undefined refere nce to `_all_signals_blocked_p' interrupt.o: In function `blockables_blocked_p': /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:280: undefined refere nce to `_blockable_sigset' /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:280: undefined refere nce to `_all_signals_blocked_p' interrupt.o: In function `gc_signals_blocked_p': /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:304: undefined refere nce to `_gc_sigset' /usr/local/src/sbcl-dev/sbcl-build/src/runtime/interrupt.c:304: undefined refere nce to `_all_signals_blocked_p' collect2: ld returned 1 exit status make: *** [sbcl.exe] Error 1 make: Leaving directory `/usr/local/src/sbcl-dev/sbcl-build/src/runtime' -- "You do not really understand something unless you can explain it to your grandmother." -- Albert Einstein.