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

Calculating dependencies ... done!
Dependency resolution took 0.85 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by dev-vcs/gitolite-3.6.14::gentoo
# required by =dev-vcs/gitolite-3.6.14 (argument)
>=acct-user/git-0-r3 gitolite

!!! The ebuild selected to satisfy "acct-user/git[gitolite]" has unmet requirements.
- acct-user/git-0-r3::gentoo USE="git -gitea -gitolite"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( git gitea gitolite )

(dependency required by "dev-vcs/gitolite-3.6.14::gentoo" [ebuild])
(dependency required by "=dev-vcs/gitolite-3.6.14" [argument])