Debugging silently failing compilation aka Webpacker can’t find application.js

After that I went on a typical programmer journey to find out what might be the issue. I went to google. Webpacker can’t find application.js was indeed a discovered error and yielded various Webpacker issues. Unfortunately nothing seemed like a fix for my broken deploy and I went to read the source code. I looked for a place where Webpacker happily prints out that compilation was a success.