[Bug bootstrap/103306] parallel build hangs since r12-5234-g04c5a91d068c4ca2f09c2bc206fce00db9d1790b

["zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>]

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.