OK, the problem is at line 4014 of gcc/Makefile.in: $(MAKE) TESTSUITEDIR="$(TESTSUITEDIR)" RUNTESTFLAGS="$(RUNTESTFLAGS)" \ check-parallel-$* \ Even worse, one can inject arbitrary shell commands here, not that I can think of a scenario where it would be an actual security problem:
RUNTESTFLAGS="i386.exp=a b\"; beep\"" check-c I presume that the solution would be to re-escape the contents of RUNTESTFLAGS. Daniel