Qt4 is dead and in the process of being removed from the tree. While the fbreader project itself seems to be dead, a user has come up with a patch that ports the necessary parts of the code to build with Qt5, see $URL for the Gentoo github PR. See also: https://github.com/geometer/FBReader/issues/285
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=1c8ade17b1cc2c36b0a782a1e7d7dde2bdb64427 commit 1c8ade17b1cc2c36b0a782a1e7d7dde2bdb64427 Author: Andrey Grozin <grozin@gentoo.org> AuthorDate: 2017-10-20 14:56:15 +0000 Commit: Andrey Grozin <grozin@gentoo.org> CommitDate: 2017-10-20 14:57:36 +0000 app-text/fbreader: use Qt-5 Closes: https://bugs.gentoo.org/634780 Package-Manager: Portage-2.3.11, Repoman-2.3.3 app-text/fbreader/fbreader-0.99.4-r3.ebuild | 95 ++++ app-text/fbreader/files/fbreader-0.99.4-qt5.patch | 573 ++++++++++++++++++++++ 2 files changed, 668 insertions(+)