Error in production environment (The asset "~" is not present in the asset pipeline.)

Introduction

I got an error when deploying the original app, so I'll post it so that I can easily resolve it if the same error occurs in the future.

1. Error details

When I checked the published application, the following error screen appeared. Since the cause of the error is not clear from this screen,

Since the cause of the error is not clear from the screen above, check the error log in the terminal.

Terminal

heroku logs --tail --app hoge-app-0123

Then, I was able to confirm that there was a problem in the following part.

What I looked up

Google Translate the error log says "Asset" icon_noimage "does not exist in the asset pipeline. Was translated.

Searching the net because the asset pipeline was unknown → The function to concatenate and compress the files in the assets directory divided into multiple directories and files has appeared. → Does it mean that icon_noimage does not exist and is not connected? ?? ?? Hmm, I don't know ...

Find out more solutions ...

To error resolution

I was able to solve it by changing config.assets.compile in config/envitonments/production.rb from false to true. It seems to be used when the layout collapses in the production environment.

config/envitonments/production.rb

config.assets.compile = true

Finally

Even if there is no problem in the local environment, problems may occur in the production environment, so it has been said for a long time to deploy frequently, but I realized the meaning. In addition, I was able to realize that I lacked knowledge of system terms due to this error, so I would like to continue learning.

Reference article

TRANSNET column "Rails beginners can easily trip over the" asset pipeline "" https://www.transnet.ne.jp/2016/02/28/rails%E5%88%9D%E5%AD%A6%E8%80%85%E3%81%8C%E3%81%A4%E3%81%BE%E3%81%9A%E3%81%8Dcolnr%E3%80%8C%E3%82%A2%E3%82%BB%E3%83%83%E3%83%88%E3%83%91%E3%82%A4%E3%83%97%E3%83%A9%E3%82%A4%E3%83%B3/