[CI]: buildg times-out

[apostasie]

Description

This was first spotted in #4007 (comment) and seen again in #4044

Message is definitely coming from https://github.com/ktock/buildg/blob/main/pkg/buildkit/client.go#L83

It is unclear to me if this is somehow builkit timeouting on GHA cache (but why then?), or something else that would be buildg specific.

Tagging @ktock for insight?

Steps to reproduce the issue

No response

Describe the results you received and expected

=== RUN   TestBuilder/Debug
    builder_builder_test.go:159: 
    builder_builder_test.go:159: ======================== Pre-test cleanup ========================
    builder_builder_test.go:159: 
    builder_builder_test.go:159: ======================== Test setup ========================
    builder_builder_test.go:159: 
    builder_builder_test.go:159: ======================== Test Run ========================
    command.go:113: /usr/local/bin/nerdctl --namespace=nerdctl-test builder debug /tmp/TestBuilderDebug385954703/001
    command.go:113: Expected exit code: 0
        
        Command:  /usr/local/bin/nerdctl --namespace=nerdctl-test builder debug /tmp/TestBuilderDebug385954703/001
        ExitCode: 1
        Error:    exit status 1
        Stdout:   
        Stderr:   timed out to access cache storage. other debug session is running?
        
        Env:
        SHELL=/bin/bash
        LOGNAME=rootless
        XDG_SESSION_TYPE=tty
        HOME=/home/rootless
        LANG=C.UTF-8
        SSH_CONNECTION=::1 41924 ::1 22
        XDG_SESSION_CLASS=user
        IPFS_PATH=/home/rootless/.local/share/ipfs
        USER=rootless
        SHLVL=1
        XDG_SESSION_ID=5
        XDG_RUNTIME_DIR=/run/user/1001
        SSH_CLIENT=::1 [419](https://github.com/containerd/nerdctl/actions/runs/14111164974/job/39530341996?pr=4044#step:8:420)24 22
        DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1001/bus
        OLDPWD=/home/rootless
        _=/usr/local/bin/gotestsum
        PATH=/usr/local/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
        ***
        DOCKER_CONFIG=/tmp/TestBuilderDebug385954703/001
        NERDCTL_TOML=/tmp/TestBuilderDebug385954703/001/nerdctl.toml
    case.go:180: 
    case.go:181: ======================== Post-test cleanup ========================
--- FAIL: TestBuilder/Debug (3.13s)

What version of nerdctl are you using?

main

Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

Host information

No response