>
> > I would do something like 'emerge -1 xorg-server xorg-drivers
> > @x11-module-rebuild mesa llvm clang' then restart X and try again.
>
> Thank you for your reply.
>
> Initially, I understood the above recomendation as the suggestion to
> rebuild the packages mentioned above with different use flags.
>
> Do you think that rebuilding them with the same use flags may help?
>

It can, for example, if the major version of the kernel has changed but you
havent rebuild xorg since (I only recall having this issue once).

If you use newuse and changed-deps with emerge its probably less likely to
find other issues.


> The said problem appeared just since the intallation of the new
> Gentoo system in January-February 2018 and not since changing
> the major version of gcc this spring.
>
> P.S. clang is not installed on my Gentoo system at all.
>
>
I've checked the dependencies on my system, and firefox is pulling that in
for me, but checking the ebuilds you can see it becomes a dependency from
v60 onwards;

/usr/portage/www-client/firefox $ ls
files/               firefox-52.9.0.ebuild   Manifest
firefox-52.6.0.ebuild  firefox-60.1.0.ebuild   metadata.xml
firefox-52.8.0.ebuild  firefox-61.0-r1.ebuild
/usr/portage/www-client/firefox $ grep clang *
grep: files: Is a directory
firefox-60.1.0.ebuild:    >=sys-devel/clang-4.0.1
firefox-60.1.0.ebuild:    has_version "sys-devel/clang:${LLVM_SLOT}"
firefox-61.0-r1.ebuild:    >=sys-devel/clang-4.0.1
firefox-61.0-r1.ebuild:    has_version "sys-devel/clang:${LLVM_SLOT}"
/usr/portage/www-client/firefox $