Ruby app version issue - mimemagic

Thank you for your amazing works.
I have a trouble to bundle app under the current Ruby.
Could you update your gem file?

When I google the error, rails version looks one of the issue but it is not easy to fix gem file considering compatibilities in my place.

Gwaphics/Gemfile

Line 7 in f370f0c

gem 'rails', '~> 5.2.3'

Fetching gem metadata from https://rubygems.org/.......... 
Your bundle is locked to mimemagic (0.3.4) from rubygems repository
https://rubygems.org/ or installed locally, but that version can no longer be found in that source. That means the author of mimemagic (0.3.4) has removed it.

You'll need to update your bundle to a version other than mimemagic (0.3.4) that hasn't been removed in order to install.
Bundler Output: Fetching gem metadata from https://rubygems.org/..........
Your bundle is locked to mimemagic (0.3.4) from rubygems repository
https://rubygems.org/ or installed locally, but that version can no longer be found in that source. That means the author of mimemagic (0.3.4) has removed it.

You'll need to update your bundle to a version other than mimemagic (0.3.4) that hasn't been removed in order to install.