[Rails 5] Countermeasures for git commit failure from another branch in Docker environment

I'm creating a Rails app in my first Docker environment. Commit from another branch failed and it took a long time to resolve I will write it as a memorandum so that I can deal with the same error immediately.

Cause

Because the .postges directory was managed by git

solution

・ Describe .postgres in .gitignore → After that, even if you push it, it remains on github

Matters that are described in .gitignore but are not reflected → Please refer to this page for caching. After pushing from the commit, it disappeared from github!

After that, I created another branch and confirmed that I was able to commit and push.

However, when I switched to the branch with the error, I got the same error, so Most of the work I was doing today has disappeared. .. ..

Also, I would like to do my best from scratch! !!

Summary

I'm a beginner in programming, so I courageously posted it to Teratail, I don't get a good answer at all There are many people who don't give an answer and make a fool of themselves, so In the future, I thought that I had no choice but to improve my ability to solve errors myself (o'∀') ﾉ