I want to be able to load the gem needed to run when I run an external Ruby script using Open3 or Daemons.

I'm stuck, so please tell me.
Rais, Ruby is writing for the first time, so you may be misguided.

I wanted to run the capture3 method of Open3 from Rails to launch the daemon, but it turned out to be "cannot load Such file".

#top_controller.rb (call processing from Rails)

def daemon_start
    cmd = "/bin/app start;"
    out, err, status = Open3.capture3 (cmd)
    pout               
    perr              
    p status.exitstatus

    redirect_to root_path
end

#app (app called)

#!/usr/bin/envruby
require 'bundler/setup'
require 'daemons'
require 'pathname'

base_dir=Pathname('../../').expand_path(__FILE__)
Daemons.run(
  base_dir.join('bin/bot'),
  app_name: 'bot',
  dir_mode: —Normal,
  dir —base_dir.join('tmp'),
  log_dir —base_dir.join('log'),
  log_output —True
)

#Display contents (err)

"bin/app:3:in `require':cannot load search file --daemons(LoadError)\n\tfrom bin/app:3:i"

Here's what I've tried.

• Run app from terminal
  → Boot without any problems

• Add Gem Path in ruby-I
  US>cmd
  cmd = "ruby-I/Users/owner/.rvm/gems/ruby-2.2.0/gems/daemons-1.2.3/lib/bin/app start;"
  If you change it to , the error does not appear.
  (If you pass /Users/owner/.rvm/gems/ruby-2.2.0/gems/ in -I, it's the same as the first error.)

• Change required path to absolute path
  Similarly, no errors appear.

• Do $LOAD_PATH.unshift in the app
  $LOAD_PATH.unshift('/Users/owner/.rvm/gems/ruby-2.2.0/gems/daemons-1.2.3/lib')
  Similarly, no errors appear.
  However, as with the above two, I cannot find the required gem in the bot called by the app.

Run app from terminal
→ Boot without any problems

Add Gem Path in ruby-I
US>cmd
cmd = "ruby-I/Users/owner/.rvm/gems/ruby-2.2.0/gems/daemons-1.2.3/lib/bin/app start;"
If you change it to , the error does not appear.
(-I pass /Users/owner/.rvm/gems/ruby-2.2.0/gems/ to the first error)

Change required path to absolute path
Similarly, no errors appear.

$LOAD_PATH.unshift in app
$LOAD_PATH.unshift('/Users/owner/.rvm/gems/ruby-2.2.0/gems/daemons-1.2.3/lib')
Similarly, no errors appear.
However, as with the above two, I cannot find the required gem in the bot called by the app.

#What should the error display at that time?
(I can't find the required file in the retryable where bot is required)

/Users/owner/.rvm/gems/ruby-2.2.0/gems/retryable-2.0.2/lib/retryable.rb:1:in `require':cannot load Such file --retryable/version (LoadError)

[Question]
If you run the app from the terminal, it will work normally, so I think the problem is that the path is not passing.
It may be possible to do the same thing with all the gems as I tried above, but I would like to avoid it because there are a certain number.
Is there a better way to pass?
Please let me know anything.
I will add any missing information.
Thank you for your cooperation.

[Environment]
Rails:4.1
Ruby: 2.2.0 (used by Rails)
Ruby: 2.2.0 (used in app)