You should open a bug. '-Wl,-z,notext' flag may be needed to be added
somewhere in the build system. From man ld :
> text
> notext
> textoff
> Report an error if DT_TEXTREL is set, i.e., if the
> position-independent or shared object has dynamic
> relocations in read-only sections.
> Don’t report an error if notext or textoff.
There have been relatively recent examples of patches being added in
portage for this kind of errors, see for example :
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=91c36206566e9aebaa0d374752188acca1e49190
