Two follow-ups from the canary red->green run and scooby's review.
1. The v2 refusal in `add`/`remove` was a bare `throw`, which reaches the CLI
top level uncaught and prints the guidance under a Node stack trace. The
message *is* the point of the refusal, so it now goes through
`command.error()` — the same clean path the roster-config error uses.
Caught on canary, not in review: the unit tests asserted the message text
and passed either way.
2. The unit-template test asserted only that ConditionPathExists is present.
Presence is not effect. Added two tests for the parts that can drift in
code while that assertion still passes: the condition resolving to exactly
the file the fleet writes (%h/%i rendered against a real install), and the
launcher genuinely failing on an absent generated env (exit 64,
`missing-file`) — which is what makes the condition load-bearing rather
than decorative.
systemd is not available in the suite, so the effect itself was measured on
canary (2026-08-16), roster v2 generation 3:
with the condition: start rc=0, Result=success, ConditionResult=no,
journal "skipped, unmet condition check"
condition removed by
drop-in, nothing else: start rc=1, Result=exit-code, ExecMainStatus=64,
unit failed, "agent environment rejected: missing-file"
Canary red->green for the three commands, same v2 roster, side by side:
fleet ps 0.0.50-next.2413 rc=1 -> branch rc=0 (3 agents listed)
fleet install 0.0.50-next.2413 rc=1 -> branch rc=0
fleet remove <name> 0.0.50-next.2413 rc=1 -> branch rc=1, refusal naming
delete + apply
All three previously failed with "Fleet roster has unknown field(s):
generation." The #791 negative was measured too: the six existing
*.env.generated files were untouched by `install` (mtimes 20+ minutes older
than the run).
Gates: typecheck 0, eslint 0, prettier clean, fleet specs 382 passed, new spec
10/10 with the fix and 9/10 red against origin/next (the 10th passes there for
an unrelated reason and is annotated as such). Full suite: only
mutator-gate.acceptance.spec.ts fails, pre-existing on origin/next.
Still true and still worth saying: a correct fix here shows install rc=0 and
start rc=0 and STILL no live seat. #1240 (tmux absent) is upstream, #1241
(start reports lifecycle-complete over dead panes) and the missing agent
runtime are downstream.
Refs #1237
Reviewed-by: scooby (by git comms; cannot file a Gitea review from fomo-lin)
On a roster-v2 fleet, `ps`, `install`, `install-systemd`, `add` and `remove`
all failed in the v1 parser. The consequence was that a greenfield v2 box could
never get its unit templates placed, so nothing downstream could start.
The read-only commands get a narrow version-agnostic view of the roster
(version, socket name, holder session, and per agent name/alias/runtime).
This is deliberately not a v2 -> v1 downshift. A downshifted FleetRoster would
be accepted by generateAgentEnvValues, which would make a third writer of
fleet/agents/<name>.env.generated through the v1 mapping and break the #791
single-SSOT invariant that projectRosterV2AgentGeneratedEnv is documented to
hold. The view is too small to write a roster or an env file back from, so that
misuse is unavailable rather than merely discouraged.
So on a v2 roster `install` places the tool files and the unit templates,
enables the units, and writes no generated env at all. Env belongs to `apply`
and `regen`, both already v2-native.
That change alone would have traded an init-time failure for a boot-time one.
`install` enables mosaic-agent@<name>.service (WantedBy=default.target) without
starting it, so a reboot between `install` and the first `apply` would run
ExecStart against an absent env file and fail every seat unit, further from its
cause. The unit template now carries
ConditionPathExists=%h/.config/mosaic/fleet/agents/%i.env.generated
which skips an enabled-but-unconfigured unit cleanly and starts it on the next
start once the reconciler has written env. On v1 it is a no-op, since v1
`install` writes env itself. Found in review by scooby.
`add` and `remove` are not routed to `create` and `delete`. They are different
operations: the v1 pair edits the roster and drives systemd, the v2 pair is
documented as changing desired state without runtime actions. `add` also
collects four fields where a v2 agent requires eleven, so routing it would mean
inventing an operator's provider, alias, reasoning and tool policy. On v2 both
now fail with the real two-step sequence instead.
Tests: 8 new, 7 of which are red before this change. Includes the greenfield
case scooby asked for — `ps` on a fresh v2 install with nothing running is rc=0
and lists every agent stopped, since that is the command an operator runs to
find out why there is no seat.
Note for anyone verifying this: a correct fix here shows `install` rc=0 and
`start` rc=0 and still no live seat. #1240 (tmux absent) is upstream, #1241
(start reports lifecycle-complete over dead panes) and the missing agent
runtime are downstream. A dead pane after this change is not a regression here.
Refs #1237, #791, #1240, #1241
The two install-linker-compatibility tests still asserted the pre-isolation
behavior (mosaic skill links planted in $HOME/.claude/skills). This branch
deliberately moved the link farm into the mosaic-owned harness homes
($MOSAIC_HOME/.claude/skills) and demoted the base-install dirs to
cleanup-only legacy targets, so the tests now assert the new topology:
the skill links appear under the harness home, foreign links in the legacy
dir are preserved, and no new mosaic link is planted in the base install.
Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Dtdjx4Gxude9fwyLezCrhh
Mosaic wrote into the operator's harness base installs — ~/.claude,
~/.pi/agent, ~/.codex, ~/.config/opencode — for settings, instructions, and a
102-symlink skill farm per harness. Any experiment with hooks or gating
therefore mutated the operator's own tooling, and a broken framework change
could take out the very harness needed to repair it.
Harness home isolation
----------------------
Each runtime now reads config from a dedicated mosaic-owned home via the
harness's own config-dir variable:
claude CLAUDE_CONFIG_DIR ~/.config/mosaic/.claude
pi PI_CODING_AGENT_DIR ~/.config/mosaic/.pi (replaces ~/.pi/agent)
codex CODEX_HOME ~/.config/mosaic/.codex
opencode XDG_CONFIG_HOME ~/.config/mosaic/.opencode
These paths are manifest-UNKNOWN, so rule 3 (#791) resolves them to operator
ownership and a keep-mode upgrade can neither overwrite nor prune them.
A bare `claude` / `pi` keeps its own config AND auth, making it a structural
break-glass rather than one depending on restoring a file under pressure.
opencode is blunter than the rest: it has no dedicated variable and follows XDG,
so isolation also relocates XDG lookups for anything it spawns. Documented in
place.
mosaic-sync-skills now links into those homes and cleans the legacy farms it
previously planted in base installs. Ownership is proven by RESOLUTION, not by
name — only symlinks resolving inside the canonical/local skills dirs are
removed, mirroring the refusal already in commands/skill.js. Verified against a
real install: codex's own .system directory survived while its 102 mosaic links
were removed. Both resolution prefixes are length-checked first; an empty prefix
would make "$resolved" == "$prefix/"* match every absolute path and delete
foreign symlinks.
Immutable launch record
-----------------------
Every launch now appends one record to fleet/run/sessions/events.ndjson before
exec. Mandatory, mechanical, no model involvement.
pi rewrites its own argv to a bare `pi`, so /proc/<pid>/cmdline destroys the
launch evidence — that has already produced a confident wrong diagnosis ("this
agent bypassed the launcher"), disproved only by the parent's argv and only
because the parent had not yet exited. A record written before exec is the only
place this survives.
The path is the #797 Runtime Session Ledger, already operator-classified and
already covered by test-upgrade-manifest-guard.sh, which seeds it and proves a
populated ledger survives keep-mode upgrades — but nothing shipped ever wrote
it. This implements it in the shape that guard already asserts (0600 files under
a 0700 dir).
`mosaic` writes session.launch; launch-runtime.py appends lease.register with
the broker session id and activation capability. They correlate by an explicit
MOSAIC_LAUNCH_ID, never by pid: execRuntime uses spawnSync, so the runtime is a
child with a different pid.
Records normative fragment digests (CONSTITUTION/AGENTS/SOUL/USER/STANDARDS/
TOOLS/RUNTIME) — the same set the broker hashes for promotion, so drift is
mechanically detectable rather than a matter of judgement.
Credential-safe: env is captured as PRESENT NAMES ONLY, and argv values over
256 bytes become a sha256 + length rather than being inlined.
Also fixes CLI_VERSION resolution: '@mosaicstack/mosaic/package.json' is not in
the package exports map and always throws ERR_PACKAGE_PATH_NOT_EXPORTED.
resolveTool() uses that same failing specifier, which is why its documented
preference for bundled tools over the deployed ~/.config/mosaic copy has never
once applied — noted in place, not fixed here.
Verified on sb-it-1-dt: isolated homes written and base installs byte-identical
for all four harnesses; 408 legacy symlinks removed with 1 foreign entry
preserved; launch records paired across the spawn boundary. typecheck shows zero
errors in launch.ts (the @mosaicstack/types failures are pre-existing and
reproduce on a pristine origin/main worktree).
Part of #869
Mos (id-11) Gate-16 merge: independent APPROVE @b6f36564 (8/8, verified vs real production settings template), author id2 != approver id11, clean mosaic-coder author, CI green wp1988.
Co-authored-by: jason.woltje <[email protected]>
Co-committed-by: jason.woltje <[email protected]>