Stable zfs-kmod & stable gentoo-sources don't play together. Reproducible: Always Steps to Reproduce: 1.emerge zfs-kmod 2. 3. Actual Results: error Expected Results: ;) It works on 5.9, using 5.10 in override variable won't help.
ZFS 0.8.6 does not support kernel 5.10 See here: https://github.com/openzfs/zfs/commit/2bc66898b7056140108a4937a6557d9fe27cafc6 This is an incompatibility between stable gentoo-sources and stable zfs-kmod.
yeah there's nothing we can do here to make it compatible. you either need to stay on older kernels or install 2.0.4 we usually mark stable versions a bit conservatively, as 2.0.x has not been in production long enough. but it's possible we'll mark it soon, discussion in progress and results are mostly positive. for now, you can do something like in a file > /etc/portage/package.accept_keywords/zfs =sys-fs/zfs-2.0* =sys-fs/zfs-kmod-2.0* but it has to be your choice, not ours ;-)
Thanks. Can you point me to this discussion? Can I somehow help? Test/contribute?
Either use the unstable version of ZFS (as Georgy says, it's your decision, not ours), use the 5.4 LTS kernel, or wait for us to make a decision re stabilisation. Sorry, we know it's a bit frustrating.
just to include an example here's a pretty nasty bug with zfs and portage https://github.com/openzfs/zfs/issues/11900 it happened before and manifested again. until it's fixed 2.x is not going stable...
I'll re-open the bug for visibility, as more people will hit that soon.
closing, please proceed to https://bugs.gentoo.org/799419 waiting room