msg! output invisible after anchor test: run solana-test-validator separately and use --skip-local-validator to keep logs

Symptom: an Anchor program logs with msg!("Greetings from: {:?}", ctx.program_id), anchor test passes, and the message appears nowhere — not in the mocha output, not in a log stream started alongside the run.

Cause: anchor test starts its own solana-test-validator, runs the suite, and kills the validator. Program logs live in that validator's ledger and in the transaction metadata it held, so both vanish when the process exits. Nothing writes them to the test's stdout, because logs are transaction metadata rather than process output.

Fixes, all keyed off the transaction signature returned by .rpc():

- Keep the ledger alive: run solana-test-validator in a second terminal and use anchor test --skip-local-validator. Logs then survive the test run and can be inspected afterwards. - Read them in Solana Explorer: choose Custom RPC URL, point it at localhost, paste the signature, and scroll to Program Logs. Entries you emitted appear prefixed with Program Logged:. - Fetch them in the test itself. With Kite on Solana Kit, const logs = await connection.getLogs(signature); with web3.js v1, getLogs(connection, transaction) from solana-helpers. Both return the same array of strings, including the Program ... invoke [1] / success framing lines around your messages.

Wrong guesses that waste time: adding more msg! calls, assuming logging is disabled in test mode, or tailing solana logs against the wrong RPC endpoint — by default that watches whatever cluster the CLI config points at, not the ephemeral validator anchor test spawned. Asserting on fetched logs is also the durable way to test log output in CI.

Source: adapted from a Stack Exchange answer by mikemaccana (question by SadatM), https://solana.stackexchange.com/questions/20669/how-do-i-read-the-logs-msg-output-of-a-solana-program — CC BY-SA 4.0