Comment # 11 on bug 1133245 from Martin Li��ka

(In reply to Dr. Werner Fink from comment #9)
> From an old manual page of gcc (Leap 15.0)
> 
>  Link-time optimization does not work well with generation of debugging
>  information.  Combining -flto with -g is currently experimental and
>  expected to produce unexpected results.
> 
> now I read on Tumbleweed:
> 
>  Link-time optimization does not work well with generation of debugging
>  information on systems other than those using a combination of ELF and
> DWARF.

Correct.

> 
> may I asked what had beend changeds menawhile?

In GCC 8 we made a significant improvement of the debug info:
https://gcc.gnu.org/gcc-8/changes.html

Link-time optimization improvements:
We have significantly improved debug information on ELF targets using DWARF by
properly preserving language-specific information. This allows for example the
libstdc++ pretty-printers to work with LTO optimized executables.

It's work made by mainly by Richard Biener and it's known as 'Early LTO'. Note
that it was a significant effort and program backtraces as well as debugging
experience in gdb should be comparable to non-LTO mode.