[Bug lto/59977] lto1: internal compiler error: bytecode stream: expected tag real_type instead of error_mark

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59977

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to David Kredba from comment #3)
> Thank you.
> 
> sci-libs/vc was build with gcc 4.9 lto a few svn revisions before, other
> libraries are not built with LTO at all.
> 
> I will try vc first and then this again.

Mixing LTO bytecode from different releases (or even different SVN revisions)
isn't supported and in most cases doesn't work (in surprising ways).

Unfortunately GCC doesn't have good measures to defend itself from LTO
bytecode format changes ... :/