sys-apps/portage-2.1.10.45 has a conditional dependency on pyxattr. So, please add your ~arch keyword to dev-python/pyxattr-0.5.0 or use.mask the xattr flag in your profiles, and then add your ~arch keyword to sys-apps/portage-2.1.10.45. Thanks!
I've re-added the keywords to the portage ebuilds, and instead added "sys-apps/portage xattr" package.use.mask entries for the relevant arch profiles: profiles/arch/alpha/package.use.mask profiles/arch/m68k/package.use.mask profiles/arch/mips/package.use.mask profiles/arch/s390/package.use.mask So, now there's not need to take any action you can't or don't want to keyword dev-python/pyxattr.
alpha/m68k/s390 stable, p.use.mask removed
keyworded for ~mips and p.use.mask removed
Seems fixed except for hppa (see bug 458436).