modemmanager uses logind to handle suspend and resume. Some stuff about maybe suspending modem gracefully too, and bring things up better on resume, or something like that - can't remember details. Anyhow, this should be possible to be supported via elogind as well - just currently only systemd or systemd-login packages are supported for it. 1.8.0 also added journald support, but this already is under a separate from logind configure flag, which we can just disable on elogind systems.
There is a patch on LFS, would taht do? http://www.linuxfromscratch.org/~dj/elogind/ModemManager-1.8.2-elogind-1.patch
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=df18596081c54f8c69451c179cafd5a2ce990f2e commit df18596081c54f8c69451c179cafd5a2ce990f2e Author: Mart Raudsepp <leio@gentoo.org> AuthorDate: 2019-03-23 10:59:38 +0000 Commit: Mart Raudsepp <leio@gentoo.org> CommitDate: 2019-03-23 10:59:58 +0000 net-misc/modemmanager: add elogind support for sleep monitor Closes: https://bugs.gentoo.org/667960 Package-Manager: Portage-2.3.52, Repoman-2.3.12 Signed-off-by: Mart Raudsepp <leio@gentoo.org> net-misc/modemmanager/modemmanager-1.8.2-r1.ebuild | 129 +++++++++++++++++++++ 1 file changed, 129 insertions(+)