[sean-brydon]

What changes

Every launchd plist Shipyard writes (service.Render) said ProcessType Background. macOS throttles the CPU and disk of a Background job, and of everything it starts: the laptop agent, berthd on a Mac box, and the agents and builds berthd runs in tmux. They now say ProcessType Interactive. Linux's systemd units are unchanged; they had nothing like it.

Plists that are already installed

Login agent	How it gets the new plist
Laptop agent (dev.berth.agent)	Right away when the app updates: berth agent restart --if-stale reinstalls it.
This Mac's own box (dev.berth.berthd, app-managed)	Right away when the app updates: the agent runs berthd install --keep-listen again.
A Mac box updated with Update all / berth upgrade	berthd only swaps its binary, so on start the new berthd rewrites the line in its own plist (new service.Migrate). launchd reads it at the next load (restart or login). Running the install command again applies it at once.
Managed units / helpers on a Mac box	Reinstalled the next time something ensures them, because their rendered bytes changed.

Migrate changes only the file and never reloads a running service. It only touches a plist written for this same program and BERTH_HOME, so another install's plist, or a test's, is left alone. It matters beyond speed too: doctor's "starts at boot" and ensureAgent compare the plist byte for byte, so without it an older plist would read as "not installed".

Proof

A real berthd in an isolated HOME (a temporary ~/Library/LaunchAgents, never the real one), with a plist as v0.3.29 writes it:

before: <key>ProcessType</key><string>Background</string>
$ HOME=$S/home BERTH_HOME=$S/berth ./berthd serve --listen 127.0.0.1:17991
after:  <key>ProcessType</key><string>Interactive</string>

(berthd then stopped binding its unix socket because the scratch path was over macOS's 104-byte limit. That happens after the migration and doesn't affect it.)

On this Mac, before the change, launchd reports the laptop agent as spawn type = background (5).

=== RUN   TestUnitsRestartOnlyAfterFailure                       (now also checks Interactive)
--- PASS: TestUnitsRestartOnlyAfterFailure (0.00s)
=== RUN   TestMigrateBringsAnOlderPlistUpToDateWithoutReloading  (other program untouched, Installed after, idempotent, no launchctl)
--- PASS: TestMigrateBringsAnOlderPlistUpToDateWithoutReloading (0.00s)
=== RUN   TestMigrateWithoutAPlist
--- PASS: TestMigrateWithoutAPlist (0.00s)
ok  	github.com/cosscom/shipyard/internal/service

go vet ./... and go test -race ./... pass, except internal/box's TestAttachPassesShiftEnter, which fails the same way on main with this Mac's tmux 3.7c. The docs build passes.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
berth	Ready	Preview	Oct 21, 2026 12:23pm UTC
berth-docs	Ready	Preview	Oct 21, 2026 12:23pm UTC

[linear-code]

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