Install this version:
emerge -a =app-emacs/eldoc-mouse-nov-0.1.1
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =app-emacs/eldoc-mouse-nov-0.1.1
Or alternatively:
emerge --autounmask-write -a =app-emacs/eldoc-mouse-nov-0.1.1
# automatically generated by g-sorcery
# please do not edit this file
EAPI=8
REPO_URI="https://elpa.nongnu.org/nongnu/"
SOURCE_TYPE="tar"
REALNAME="eldoc-mouse-nov"
DIGEST_SOURCES="yes"
inherit g-sorcery gs-elpa
DESCRIPTION="Preview epub link for mouse hover"
HOMEPAGE="https://github.com/huangfeiyu/eldoc-mouse-nov"
SRC_URI="${REPO_URI}${REALNAME}-${PV}.${SUFFIX}"
SLOT="0"
KEYWORDS="~amd64 ~x86"
DEPEND="app-emacs/eldoc-mouse
app-emacs/nov"
RDEPEND="app-emacs/eldoc-mouse
app-emacs/nov"
app-emacs/eldoc-mouse app-emacs/nov
app-emacs/eldoc-mouse app-emacs/nov