Incus launch crashes incus daemon and fails with: websocket: close 1006 (abnormal closure): unexpected EOF [solved]

Incus
1

I’m trying to get incus setup for the first time. I have pretty much default settings, though I did change the default network. When I launch a new container with incus launch images:ubuntu/22.04 test I get the error message Error: Failed instance creation: websocket: close 1006 (abnormal closure): unexpected EOF and the incus daemon crashes. What is causing this and how can I fix it?

I’ve tried with a custom image too and get the same error. OS is Gentoo Linux, kernel is 6.13.5, incus version is 6.10.1.

My default profile: View paste W4QA
My network: View paste R3HQ

2

Can you look at the journalctl output when Incus crashes so you can fetch the actual stack trace of the crash?

3

I’m not using systemd, but all I see in the syslog are some messages about dnsmasq when incus starts. Nothing on the crash. I built incus with debug symbols, but I’m not sure what options I need to run incusd manually.

4

Okay, found default options. All I was missing was the --group incus-admin option.

Output on crash:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x561f15fc06b9]

goroutine 704 [running]:
github.com/lxc/incus/v6/internal/server/instance/drivers.(*lxc).findIdmap(0xc000badb00)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/instance/drivers/driver_lxc.go:491 +0x439
github.com/lxc/incus/v6/internal/server/instance/drivers.lxcCreate(_, {0x13, {0xc00189e4bc, 0x4}, 0x0, 0x0, {0xc00189e4b0, 0x7}, {0x0, 0x0}, ...}, ...)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/instance/drivers/driver_lxc.go:272 +0x1045
github.com/lxc/incus/v6/internal/server/instance/drivers.create(_, {0x13, {0xc00189e4bc, 0x4}, 0x0, 0x0, {0xc00189e4b0, 0x7}, {0x0, 0x0}, ...}, ...)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/instance/drivers/load.go:146 +0x16e
github.com/lxc/incus/v6/internal/server/instance.CreateInternal(_, {0x13, {0xc00189e4bc, 0x4}, 0x0, 0x0, {0xc00189e4b0, 0x7}, {0x0, 0x0}, ...}, ...)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/instance/instance_utils.go:1023 +0x1435
main.instanceCreateFromImage({_, _}, _, _, _, {0x0, {0x0, 0x0}, 0x0, 0x0, ...}, ...)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/cmd/incusd/instance.go:161 +0x297
main.createFromImage.func1(0xc00111a280)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/cmd/incusd/instances_post.go:139 +0x585
github.com/lxc/incus/v6/internal/server/operations.(*Operation).Start.func1(0xc00111a280)
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/operations/operations.go:286 +0x26
created by github.com/lxc/incus/v6/internal/server/operations.(*Operation).Start in goroutine 638
        /var/tmp/portage/app-containers/incus-6.10.1/work/incus-6.10.1/internal/server/operations/operations.go:285 +0x105

I also see this output running incusd (pre-crash):

ERROR  [2025-03-12T21:37:16-07:00] Unable to parse system idmap                  err="No map found for user"                   
WARNING[2025-03-12T21:37:16-07:00] AppArmor support has been disabled because of lack of kernel support                        
WARNING[2025-03-12T21:37:16-07:00]  - AppArmor support has been disabled, Disabled because of lack of kernel support 
WARNING[2025-03-12T21:37:16-07:00]  - Couldn't find the CGroup memory swap accounting, swap limits will be ignored

I’m not using AppArmor, but the idmap error might be related.

5

Yep, the idmap error is the cause of it.

6

Any idea how to resolve this? I haven’t touched anything with idmap.

7

Your system has /etc/subuid and /etc/subgid but no mapping for the root user.

You seem to be using Gentoo or a derivative, so following the install instructions for Gentoo should fix this: https://wiki.gentoo.org/wiki/Incus#Installing

8

Oh you’re right. Thanks, I guess I missed that when I was installing.

9

I pushed a fix now which will avoid the crash in the future (erroring out instead).

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