--- Comment #5 from John Paul Adrian Glaubitz <glaubitz at physik dot
(In reply to Jeffrey A. Law from comment #4)
> We would need the cpp output to thoroughly analyze this. You can get the
> cpp output using "-save-temps" on the comment line and passing along the
> generated .ii file.
> This may be fixed or it may have just gone latent. It's hard to tell
> without having that .ii file.
So, gcc-8 (r257435) itself builds fine  but the latest gcc-snapshot we have
in Debian unstable still fails , but that version might be older than the
gcc-8 package in unstable.
I'll watch out for the next gcc-snapshot upload to Debian unstable and see if
the problem still persists. As you said, it might have already been fixed.
In the meantime, I willl try to generate the preprocessed source and attach it
to the bug report.