| 8 Feb 2026 |
 ma27 | Any opinions from infra about https://github.com/NixOS/nixpkgs/pull/478109#discussion_r2720782908 ? | 19:16:22 |
 hexa | intriguing | 19:23:49 |
| hexa | we don't currently have cgroups xp enabled | 19:27:39 |
| hexa | iirc only lix has a working implementation at this time | 19:27:56 |
| hexa | commit ae6761b9fea22ac802ead7757d034665cb4e795e
Author: Martin Weinelt <hexa@darmstadt.ccc.de>
Date: Sun Mar 2 23:04:26 2025 +0100
builders: stop using cgroups for now
They currently break the build of nixosTests.systemd-boot.extraEntries on
lix 2.91.1 and nix 2.25.2 after the edk2 202502 upgrade.
The test hangs in nixos-disk-image-aarch64-linux with
> Press ESC in 5 seconds to skip startup.nsh or any other key to continue.
> Press ESC in 4 seconds to skip startup.nsh or any other key to continue.
> Press ESC in 3 seconds to skip startup.nsh or any other key to continue.
> Press ESC in 2 seconds to skip startup.nsh or any other key to continue.
> Press ESC in 1 seconds to skip startup.nsh or any other key to continue.
> [hangs here]
And aborting the test after it times out fails with
> Aborted: error: deleting cgroup '/sys/fs/cgroup/system.slice/nix-daemon.service/nix-build-uid-30022': [Device or resource busy]
| 19:28:35 |
 K900 | Ugh | 19:29:02 |
| K900 | Not a fan of the whole thing at all tbh | 19:29:03 |
| K900 | Bolting on more wacky nonsense on the test driver is not the way | 19:29:04 |
| K900 | But rewriting it to be actually good is spoons | 19:29:06 |
| hexa | have you looked at the implementation and is it wacky? | 19:30:05 |
| hexa | * have you looked at the implementation and are you considering it wacky? | 19:30:11 |
| K900 | A little and yes | 19:30:19 |
| hexa | more lightweight tests would surely be appreciated | 19:30:21 |
 raitobezarius | the biggest problem of this is not cgroups | 19:32:56 |
| raitobezarius | it's auto-allocate-uids and uid-range | 19:32:59 |
| raitobezarius | there's no implementation ready for that in any interpreter | 19:33:08 |
| raitobezarius | notably blocked on https://github.com/NixOS/nixpkgs/pull/404864 | 19:33:15 |
| raitobezarius | (and sure, there's a PR for nsresourced integration in cppnix) | 19:34:22 |
 Arian | Yeh for now this means running tests outside of nix right? | 19:48:44 |
| Arian | Honestly my dream setup would be new test driver and then we can just use vmspan or nspawn (they have basically identical interfaces) | 19:51:31 |
| Arian | But yeh that's .. work | 19:51:40 |
| Arian | Especially driver that integrates with all the systemd goodies like the notify vsock stuff would be great | 19:52:25 |
| raitobezarius | In reply to @arianvp:matrix.org
Yeh for now this means running tests outside of nix right? That code uses uid-range | 19:52:49 |
| raitobezarius | So you cannot run it outside of Nix | 19:53:00 |
| Arian | Oooh | 20:01:34 |
| ma27 | fwiw I think the implementation improved quite a lot with the latest few commits and doesn't walk into a wrong direction design-wise. So, IMHO it's perfectly fine to start with this and iterate on that once we actually can use nsresourced (I've heard about ideas to implement this since ~2017). | 20:49:57 |
| K900 | I may need to skim it again | 20:50:13 |
| ma27 | excuse my ignorance, but now that I think of it, how feasible is it to have nsresourced et al. inside a sandbox? | 20:50:42 |
|  @corngood:corngood.com left the room. | 21:23:29 |
| raitobezarius | In reply to @ma27:nicht-so.sexy
excuse my ignorance, but now that I think of it, how feasible is it to have nsresourced et al. inside a sandbox? By some alignment of all the stars, we, at Lix, need uid-range stabilized to enable xattrs in the store, coincidentally, getting nspawn for our own test suite would make us happier as well, nsresourced is already mentioned in https://git.lix.systems/lix-project/lix/issues/387#issuecomment-12929 (and this is an idea that has been floating back when the systemd crew introduced it at some ASG before that comment) | 21:42:42 |
