gtk-sharp needs an outdated automake

[bunder2015]

Hi, I know gtk2 is old nowadays, but is it possible to build gtk-sharp with a newer automake? Thanks

# emerge -av gtk-sharp

These are the packages that would be merged, in order:

Calculating dependencies... done!

!!! All ebuilds that could satisfy "sys-devel/automake:1.11" have been masked.
!!! One of the following masked packages is required to complete your request:
- sys-devel/automake-1.11.6-r3::gentoo (masked by: package.mask)
/var/db/repos/gentoo/profiles/package.mask:
# Andreas K. Hüttel <dilfridge@gentoo.org> (2017-10-18)
# sys-devel/automake versions 1.4, 1.5, 1.6, 1.7, 1.8
# have known security vulnerabilities, are broken with
# recent Perl (>=5.26.0), and are not used by anything in
# the Gentoo repository. Please uninstall.


(dependency required by "dev-dotnet/gtk-sharp-2.99.3-r1::dotnet" [ebuild])
(dependency required by "gtk-sharp" [argument])
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.