Rails errors GemNotFoundException

calendar2022-02-15 · 2 min read · ruby ruby-on-rails rvm  ·
Share on: linkedincopy

You recently installed rails but since you're still learning, you did a lot of stuffs. One day, you got the following error:

1~$ rails --version
2Traceback (most recent call last):
3        2: from /usr/local/bin/rails:23:in `<main>'
4        1: from /usr/lib/ruby/2.7.0/rubygems.rb:294:in `activate_bin_path'
5/usr/lib/ruby/2.7.0/rubygems.rb:275:in `find_spec_for_exe': can't find gem railties (>= 0.a) with executable rails (Gem::GemNotFoundException)

Probably, you forgot that you switched gemset?

Check contents of your gemdir

 1~$ cd `rvm gemdir`
 2~$ pwd
 3/home/user/.rvm/gems/ruby-2.7.2@newname
 4~$ ll
 5total 24
 6drwxr-xr-x 5 user user 4096 Feb 16 11:54 ./
 7drwxr-xr-x 8 user user 4096 Feb 16 11:54 ../
 8drwxr-xr-x 2 user user 4096 Feb 16 11:54 bin/
 9drwxr-xr-x 2 user user 4096 Feb 16 11:54 cache/
10-rw-r--r-- 1 user user  516 Feb 16 11:54 environment
11drwxr-xr-x 2 user user 4096 Feb 16 11:54 wrappers/

The above directory listing shows no gems are installed yet.

Check version you need

1~$ gem search '^rails$' --all

Install Rails

1~$ gem install rails -v  7.0.2.2

Check contents of gemdir again

 1~$ ll `rvm gemdir`
 2total 44
 3drwxr-xr-x 10 user user 4096 Feb 16 12:04 ./
 4drwxr-xr-x  9 user user 4096 Feb 16 12:01 ../
 5drwxr-xr-x  2 user user 4096 Feb 16 12:04 bin/
 6drwxr-xr-x  2 user user 4096 Feb 16 12:04 build_info/
 7drwxr-xr-x  2 user user 4096 Feb 16 12:04 cache/
 8drwxr-xr-x 41 user user 4096 Feb 16 12:04 doc/
 9-rw-r--r--  1 user user  531 Feb 16 12:01 environment
10drwxr-xr-x  3 user user 4096 Feb 16 12:04 extensions/
11drwxr-xr-x 41 user user 4096 Feb 16 12:04 gems/
12drwxr-xr-x  2 user user 4096 Feb 16 12:04 specifications/
13drwxr-xr-x  2 user user 4096 Feb 16 12:04 wrappers/

Notice that the directory contents are different now and rails will no longer show an error

1~$ rails --version
2Rails 7.0.2.2