Hi. Thanks a lot for addressing the issue.
So, trying to render the Django template serial_console.html, compress fails, when it see 'inline-blo'. IMO, it must be: display:inline-block; from the file openstack_dashboard/static/dashboard/scss/serial_console.scss. At first glance, I didn't get it, but looking further, when doing a grep, it appears that the "display:inline-block" in this file is the only one I can see in the whole horizon source code that doesn't have a space after the semi-column. This may be it!
This may be indeed.
At the current moment, what I've done was this commit: https://salsa.debian.org/openstack-team/services/horizon/-/commit/5798795e33880c0225aaf298a9a82f4aecfda14d This is a workaround which I would prefer to avoid: by deleting the serial_console.html Django template, I'm breaking one of the Horizon functionality. One that most people wont use (everyone uses VNC), though I'd prefer to not do that. So, I was wondering, if you know how to reproduce (which so far I haven't been able to on my laptop or otherwise), could you try the trick of adding a space in "display:inline-block" in serial_console.scss and see if that's enough to fix it?
Actually, I don't really know how to reproduce it, because it happens randomly with a probability between 5%-10%, and my current setup does not allow me to test modified packages easily, only packages from stable, testing or unstable. But I can test it very easily if you make an upload for unstable which adds the missing space. Then I will gladly build the package in unstable lots of times in lots of machines and can tell you if the problem is actually gone or not, which I believe it is very likely given your above explanation. Thanks.