CI flake: daemon.test.ts RPC ports inside Linux ephemeral range cause EADDRINUSE

[Rinse12]

Symptom

Master CI run 26397296711 failed on ubuntu-latest with:

FAIL test/cli/daemon.test.ts > bitsocial daemon webui
Daemon failed to start: listen EADDRINUSE: address already in use :::39138

27 of 28 test files passed; the bitsocial daemon webui suite died in beforeAll. macOS and Windows passed. Kubo bringup succeeded (Kubo IPFS API listening on 0.0.0.0:50189, Daemon is ready), then the PKC RPC bind to 39138 hit EADDRINUSE.

Root cause

test/cli/daemon.test.ts hardcodes RPC ports 11138, 19138, 29138, 39138, 49138, 59338, 59339. All of these sit inside Linux's default ephemeral port range (/proc/sys/net/ipv4/ip_local_port_range = 32768 60999).

Any outbound TCP connection on the runner — another vitest worker's kubo libp2p connection, GitHub Actions agent polls, npm registry traffic, system DNS, etc. — can have the kernel assign it one of those exact ports as its source port. While held, no one can listen() on it. On this run, something on the ubuntu-latest runner had :::39138 bound when the webui daemon tried to start.

The recent fail-fast PR (#47) is why the failure surfaces cleanly as Daemon failed to start: listen EADDRINUSE :::39138 rather than getting buried later. The flake itself predates that PR.

Why "use a high port" doesn't fix it

OS	Default ephemeral range
Linux	32768 – 60999
macOS	49152 – 65535
Windows (Vista+)	49152 – 65535

The only window outside the ephemeral range on all three matrix OSes is roughly 1024 – 32767. That's where the already-safe ports in this file (9338, 9388, 9348) sit.

Fix

Move the seven hardcoded RPC ports into the safe 9148 – 9208 block (no collisions with any other test file or src/common-utils/defaults.ts):

Current	New	Describe
11138	9148	--pkcRpcUrl
19138	9158	PKC_RPC_AUTH_KEY env var
29138	9168	KUBO_RPC_URL env var
39138	9178	webui (the failing one)
49138	9188	kills kubo on shutdown
59338	9198	DEBUG env var #1
59339	9208	DEBUG env var #2

Out of scope

The 50xxx Kubo ports in this file are also inside the Linux ephemeral range and could flake the same way, but haven't been observed to. Leaving for a follow-up.