[Bug web/82686] Debian sid powerpc64-unknown-linux-gnu 4.13.0-1-powerpc64 bootstrap breaks in stage3 with unexpected requirement for bdw-gc

[dclarke at blastwave dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82686

--- Comment #10 from Dennis Clarke <dclarke at blastwave dot org> ---
I had not yet tested a build of gcc previous to gcc 7.x regarding
this issue.  Seemed counter intuitive to revert backwards but now
I have to agree that "something changed" again in the world of
doing a bootstrap of gcc.  This seems to be happening more and more
and getting gcc to reasonably build is becoming more and more of
a black art as opposed to a science. 

I will, for the sake of experimentation, go try a bootstrap of 
the gcc 6.4.0 and then if that works out move on to 7.3.0.

I know that our friend Jonathan Wakely in comment 5 of this bug
report. Also there is question if this is a bug at all. I tend
to look at the existence of a bootstrap problem based on testing
across multiple platforms and I can not run into this same problem
on a sparc based Solaris 10 server wherein I do get multi-arch or
at least multi-lib successful build results.  There are no test 
results posted on the GCC site anymore : 

    https://gcc.gnu.org/gcc-7/buildstat.html

That seems to have died at least a year ago or more so it is 
very difficult to search the vast noise of the maillist using
some format https://gcc.gnu.org/ml/gcc-testresults/YYYY-MM/ as
a target string and then the platform and version.  Simply said
it is becoming more and more a black art.

Jonathan says " This library needs to be available for each
multilib variant"  from the docs however this is not true at
all on some platforms. Certainly sparc has no issues. 

I will try gcc 6.4.0 for the sake of a test and then move onwards.

Dennis Clarke