`vm run` took 41s cold / 30s warm to run `true`. Both were vmbox waiting on
itself. Now 12s / 0s, with all five shutdown verdicts re-tested unchanged.
- _run_settle waited up to 30s for the kernel's "reboot: Power down" marker
UNCONDITIONALLY, including on the majority of runs that leave the guest up,
where that marker is never going to appear. It now settles only when the
guest has actually stopped, or when ssh returned 255 (what a successful
poweroff looks like from the host).
- The ssh readiness polls used a 5s ConnectTimeout. QEMU's user-mode
networking ACCEPTS the forwarded connection while the guest still has
nothing on :22, so each probe blocked for the full timeout instead of
failing fast: a guest reachable at ~10s was reported up at ~45s. Fixed in
both the sandbox and build paths, via an env override -- ssh honours the
FIRST value for an option, so a second -o could not have worked.
Making runs fast exposed a race: sshd now answers BEFORE tty1's autologin has
started Xorg, so the X environment could be missing on the first run after a
boot. `VMBOX_X_WAIT=<seconds>` waits for the session; it defaults to 0 so an
ordinary run never pays for a graphical session it is not using.
Build: the host's /var/cache/pacman/pkg is offered to the build guest
read-only (`readonly=on` AND an `ro` mount, because it is the real host cache)
as an extra CacheDir after the guest's own writable one, so a package the host
lacks still downloads rather than failing the build. This removes the 396 MiB
the build used to fetch. Host cache verified byte-for-byte identical across
four builds: same file count, same size, same mtime.
Build time itself moved only 103.8s -> 100.3s. Per-phase timings (also added
here) show why: 47s of it is the build guest's cloud-init first boot, and that
is NOT datasource probing -- `cloud-init analyze blame` totals 2.27s. Left
unexplained rather than guessed at; SESSION_RESULTS.md records the evidence.
Also: `vm scp`, which lib/ssh.sh could always do but the CLI never exposed,
and provision.sh split at the 250-line cap.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
Much of testsAndMisc/linux_configuration cannot be tested on the host: 15
files use `chattr +i` (so a bad test is not simply revertable), the shutdown
installers write units that power the machine off, and boot_recovery installs
pacman hooks. The repo's own CI says as much -- its Ubuntu job runs only the
side-effect-free tests, noting the rest "drive pacman, /etc, systemd or adb".
vmbox runs them in a throwaway Arch guest and verifies the result from the
HOST, which is the part that is not obvious: a successful shutdown kills the
connection carrying the report, and ssh returns 255 for a clean poweroff, a
crash and a dropped link alike. So the verdict comes from two artefacts that
outlive the VM -- a QMP event log written by a recorder attached at launch
(attach later and qemu has already exited), and the serial console log.
Five outcomes are distinguished: clean poweroff (SHUTDOWN guest:true plus a
serial tail reaching "reboot: Power down"), dirty stop, guest-reset (rebooted
instead of powering off), GUEST_PANICKED, and hung. A POWERDOWN event proves
nothing -- it means the request was delivered, not that anything acted on it.
Reset is a qcow2 backing-file trick: the golden image is built once and sealed
(chmod 444 plus a sha256 sidecar verified on every launch, since booting the
base would silently invalidate every overlay), and each sandbox is a thin
overlay, so reset is rm + recreate. No root anywhere -- user-mode networking
with per-VM forwarded ssh ports, and a socket multicast segment for VM-to-VM.
The guest clock is pinned and re-applied on every launch, because the shutdown
installers gate on a 21:00-05:00 window; NTP is masked in the image or it
silently undoes the pin. Repos are cloned from a read-only share scoped to an
explicit directory, never $HOME, and credentials are sentinel values.
`vm build` ends by booting a throwaway sandbox off the sealed image and
refusing to ship if ssh does not answer. Several distinct faults produced an
identical "boots fine, connection reset" symptom; checks inside the build VM
only prove state at seal time, so the gate has to be an end-to-end boot.
Tests: 8 bats cases over the verdict table and name/meta/serial handling;
shellcheck and ruff clean; every file within the 250-line cap.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
