The IT suite uses Cargo to start embedded Tomcat instances against a PostgreSQL + pgvector container. Most IT failures are environmental, not code defects — port conflicts, container leaks, or running with the wrong Maven flags.
When you see red and don't yet know whether it's your code or the test harness.
The IT modules under wikantik-it-tests/ each run their own Tomcat via
Cargo. They use fixed ports (8080 for HTTP, 8205 for RMI) so parallel
execution always conflicts. The pgvector container also uses a fixed
port (55432), and Docker doesn't always release it cleanly between
runs.
The wikantik-main module has a known set of parallel-flake unit tests
(per MEMORY.md) — they pass in isolation. They show up in unit-test
runs, not IT runs, but agents sometimes confuse the two.
The frontmatter steps are the canonical first-aid sequence. Steps
1–3 catch the environmental issues; step 4 narrows scope; steps 5–6
locate the actual error.
The frontmatter pitfalls are the recurring traps. The -T 1C flag
is by far the most common cause — agents copy unit-test commands into
IT contexts without editing.