https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103306
--- Comment #5 from Zdenek Sojka <zsojka at seznam dot cz> --- $ make --version GNU Make 4.3 Built for x86_64-pc-linux-gnu Copyright (C) 1988-2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. $ grep -C5 'Cannot access ' gcccompile.log Applying io_quotes_use to xorg/xorgVersion.h Applying io_quotes_use to xorg/xf86Module.h Applying strict_ansi_only to xorg/compiler.h Fixed: xorg/compiler.h Quoted includes in xorg/compiler.h Cannot access CL/cl_ext.h: No such file or directory Cleaning up unneeded directories: fixincludes is done echo timestamp > stmp-fixinc if [ -d include ] ; then true; else mkdir include; chmod a+rx include; fi if [ -d include-fixed ] ; then true; else mkdir include-fixed; chmod a+rx include-fixed; fi I might be hitting the "Some really strange error happened." situation Disabling ccache does not help. Reverting the fixincludes patch on current master (r12-5347) fixes the parallel build for me.