Yunlian should drive this (find who can help or fix himself)

In the /etc/portage/package.keywords/cross-x86_64-cros-linux-gnu

I see
cross-x86_64-cros-linux-gnu/libcxx amd64 ~amd64

If I remove ~amd64, it can choose the right ebuild.

This line was added by crossdev.

in the function 
set_keywords(), it sets the KEYWORDS based on the ${ver} associated with the packages. For extra packages (go, libcxx, libunwind), we do not set the ${ver} in the crossdev and set_keywords set the keywords to 
            keywords="${TARCH} ~${TARCH}";;
in 

                case ${ver} in
                        "[stable]") keywords="${TARCH}";;
                        *)          keywords="${TARCH} ~${TARCH}";;
                esac

Can we remove the line 
*)          keywords="${TARCH} ~${TARCH}";;

to make it work?

Mike, does comment #3 make sense?
should I prepare a patch for review?

ping? 

i don't think deleting that line is correct.  it defeats the whole point of having [stable] version markers and you'd break default crossdev usage everywhere.

crossdev's API atm is limited when it comes to extra packages.  they should be extended, but that looks a bit of a yak shave you guys don't want to get into.

i see that really --ex-pkg should be respecting DEFAULT_VER but isn't.  so can you make that change ?
-        XVER=${XVERS[i]} \
+        XVER=${XVERS[i]:-${DEFAULT_VER}} \

we should change cros_setup_toolchains to call crossdev with --stable instead of manually passing --gcc/--binutils/etc... in with "[stable]".  you can land that now w/out the crossdev change and make sure things don't break.  then test that the crossdev change itself is OK.

[It appears that a bunch of old cros issues bulk-added the "Infra" component recently, but they should probably be "Infra>Client>ChromeOS".]

We do not need this feature anymore, so mark this is won't fix.