https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67116
--- Comment #4 from Cezary Śliwa <sliwa at ifpan dot edu.pl> --- OK, the newly built compiler cannot be used because we are cross-compiling. The only thing that can be done is to move the trees to the target system and finish building target libraries there. A warning or error message could be a good idea, but otherwise you can close this bug report.
