current version 1.12.0 gives 404 on trying to download. Looking at their github list of versions, 1.12.1 is available, with a 1.13 version in beta. Simply renaming the 1.12.0 ebuild gile to 1.12.1 seems to work fine (I've installed, but not actually used yet.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=78b980d346bf4c8002acbbf2f56a29b08df150d2 commit 78b980d346bf4c8002acbbf2f56a29b08df150d2 Author: Amy Liffey <amynka@gentoo.org> AuthorDate: 2018-06-24 10:36:07 +0000 Commit: Amy Liffey <amynka@gentoo.org> CommitDate: 2018-06-24 10:39:05 +0000 net-im/signal-desktop-bin: version bump 1.13.0 Closes: https://bugs.gentoo.org/658614 Package-Manager: Portage-2.3.40, Repoman-2.3.9 net-im/signal-desktop-bin/Manifest | 1 + .../signal-desktop-bin-1.13.0.ebuild | 57 ++++++++++++++++++++++ 2 files changed, 58 insertions(+)