767 JSON :: ParserError occurs and the problem that the local server cannot be started

When entering the rails s command on the terminal, The following error log occurred during the server startup process, and the local server startup failed.

#Lines above the 10th line are omitted
	10: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/2.6.0/tsort.rb:228:in `block in tsort_each'
	 9: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/railties-6.0.3.3/lib/rails/initializable.rb:61:in `block in run_initializers'
	 8: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/railties-6.0.3.3/lib/rails/initializable.rb:32:in `run'
	 7: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/railties-6.0.3.3/lib/rails/initializable.rb:32:in `instance_exec'
	 6: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker/railtie.rb:84:in `block in <class:Engine>'
	 5: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker.rb:35:in `bootstrap'
	 4: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker/commands.rb:25:in `bootstrap'
	 3: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker/manifest.rb:18:in `refresh'
	 2: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker/manifest.rb:84:in `load'
	 1: from /Users/ito/.rbenv/versions/2.6.5/lib/ruby/2.6.0/json/common.rb:156:in `parse'
/Users/ito/.rbenv/versions/2.6.5/lib/ruby/2.6.0/json/common.rb:156:in `parse': 767: unexpected token at '' (JSON::ParserError)

When I read the error content for the time being, parse': 767: unexpected token at '' (JSON::ParserError) Pay attention to the display of. What the hell is this? I think, I will continue to search for a solution.

What was investigated and hypothesis

For the time being, I searched with JSON :: ParserError, but I couldn't find any information about it. Meanwhile, the information on the following site became a source of light.

Developer mode blog: rails 6 wasting precious 4 hours in the afternoon

... I'm falling here. When I followed it, there was a file called manifest.json under public / packs, which was empty. I must have gone to make this file when it got stuck. I forced a reset there, so it remained empty, which seems to give a JSON-ParseError. I deleted this file and it worked. Was good.

Hmmm, in short ** the file for ruby itself is corrupted ** and ... In retrospect, I remembered ** killing the server with Control + C while processing the local server **. As with the above symptoms, hypothesize that ** manifest.rb may have been corrupted **, I tried to save manifest.rb to another directory (such as desktop) so that it would not be read.

as a result

Based on the hypothesis and the contents investigated, save manifest.rb to another directory (desktop) and execute rails s again. Then, the following result was returned.

`Terminal`


/Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.8/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:
in `require': cannot load such file -- 
/Users/ito/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/webpacker-4.3.0/lib/webpacker/manifest.rb (LoadError)

... Well, I thought it would be like this, but I was shocked to run into the dark grounding again here. It seems that it was not solved without loading manifest.rb. ~~ It doesn't seem to be automatically generated in the first place ~~

I couldn't find a valid solution on the internet anymore, so I decided to ask a question to the mentor of TECK CAMP. It is impossible to solve the error occurring in the unknown dark area by yourself.

But ..., no ...!

It was a bug whose solution was unknown to the mentor. I'm sorry to have done various things, but the operation of my Mac Book became too heavy, so I took a break here. It's already Yannarune.

And the solution

Looking back at the contents of Developer mode blog: rails 6 wasting precious 4 hours in the afternoon View.

・・・ ** There is a file called manifest.json ** under public / packs ...

**Hmm? ** If you look closely, you haven't said a word to delete manifest.rb!

Then check the directory immediately. There is an empty manifest.rb ...! Delete manifest.rb while wkwk. As a result, the local server has been successfully revived. Congratulations

The cause was ** the manifest.json ** in the public / packs directory of the Rails app I'm working on. I wonder why I overlook it because it was written in the reference blog. The Ruby file wasn't corrupted.

I was terrified by my self-confidence reading comprehension, and this solved the 767 JSON :: ParserError. I wasted 3 hours ... I don't use Control + C lightly anymore ...