I haven’t yet updated my server to Leap 15.3 so I haven’t run into this particular issue yet, but it works on Leap 15.2 and Tumbleweed (with the same package) so I agree this points towards a kernel version or some other system package version issue.
@Joshua_Newman Sorry for not responding to the BZ you opened – I did take a look at it when you first opened it but I’ve been chasing down other LXD issues on openSUSE that I didn’t get around to looking into this one deeply.
I’m having the same issue on a fresh install of openSUSE Leap 15.3. Looking forward to a fix or workaround!
Well ok. This is an unexpected twist… It seems that the OpenSUSE kernel has my close_range() syscall backported but not CLOSE_RANGE_UNSHARE (which was in the first version. So that’s why this is all messed up.
See
please.
lxc exec works with the fix now, thank you!!
Containers I create are not getting DHCP leases, but this might be an error on my part; not sure yet.
If you’re running the snap package it could well be related to one of these:
I’m using the packages in the openSUSE official repositories, except for the lxd package which I built myself to include the lxc exec fix, but I’ll read those just in case anything might apply.
Check dnsmasq is running, and if so then check your firewall isn’t preventing DHCP requests.
Ahhh it was the firewall! Definitely did not expect that. 
Thank you very much!
Perfect, that did the trick.
Thanks much for the very quick turnaround @brauner!
I’ve backported the patch to the openSUSE packages, it should appear in Leap in a little while (in the meantime, you can use the devel packages in Virtualization:containers).