It installs a single file, and doesn't need to depend on app-shells/zsh for that. Please install the file unconditionally.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=15ae64bfc8ffd6047e48596c0f820a1b2152700f commit 15ae64bfc8ffd6047e48596c0f820a1b2152700f Author: Mike Gilbert <floppym@gentoo.org> AuthorDate: 2018-11-20 15:10:32 +0000 Commit: Mike Gilbert <floppym@gentoo.org> CommitDate: 2018-11-20 15:10:32 +0000 dev-util/ninja: install zsh completions unconditionally Closes: https://bugs.gentoo.org/671544 Package-Manager: Portage-2.3.51_p14, Repoman-2.3.12_p5 Signed-off-by: Mike Gilbert <floppym@gentoo.org> dev-util/ninja/ninja-1.8.2-r1.ebuild | 9 +++------ dev-util/ninja/ninja-1.8.2-r2.ebuild | 9 +++------ dev-util/ninja/ninja-1.8.2.ebuild | 11 ++++------- dev-util/ninja/ninja-9999.ebuild | 11 ++++------- 4 files changed, 14 insertions(+), 26 deletions(-)