RepoMan scours the neighborhood... dependency.unknown 1 mail-client/geary/geary-0.12.4.ebuild: DEPEND: dev-lang/vala:0.44 Note: use --include-dev (-d) to check dependencies for 'dev' profiles RepoMan sez: "You're only giving me a partial QA payment? I'll take it this time, but I'm not happy."
!!! The following update has been skipped due to unsatisfied dependencies: mail-client/geary:0 selected: (mail-client/geary-0.12.3:0/0::gentoo, installed) skipped: (mail-client/geary-0.12.4:0/0::gentoo, ebuild scheduled for merge) (see unsatisfied dependency below) emerge: there are no ebuilds to satisfy "dev-lang/vala:0.44". (dependency required by "mail-client/geary-0.12.4::gentoo" [ebuild])
This is to be expected with the current vala.eclass and causes no trouble whatsoever besides repoman being a bit noisy (just like it would also for perfectly valid hard blockers for migrations that are kept way after last rites, etc). For many other packages it also tells about :0.38; 0.44 is supported by eclass because 0.43 dev releases are out, and an overlay eclass can't support 0.44 SLOT for main tree ebuilds with their own eclass (they'd have to copy all the ebuilds).
Oh, your problem is not what you reported initially and put in the summary, but what you commented later - that for some reason geary isn't fine with vala:0.40 nor vala:0.42 for you. geary-0.12.4 has this dependency via eclass for vala: || ( dev-lang/vala:0.44 dev-lang/vala:0.42 dev-lang/vala:0.40 ) I don't know why you can't see 0.40 or 0.42 as options. Probably mixing keywords.