Bundler: can't find gem bundler (>= 0.a) with executable bundle (Gem::GemNotFoundException) during bundle install with gem

Question

I'm executing the following script:

gem install rdoc --no-document
gem install bundle
bundle

output:

+ gem install rdoc --no-document
Successfully installed rdoc-6.1.1
1 gem installed
+ gem install bundle
Successfully installed bundle-0.0.1
Parsing documentation for bundle-0.0.1
Done installing documentation for bundle after 2 seconds
1 gem installed
1 gem installed
+ bundle install
/usr/lib/ruby/2.5.0/rubygems.rb:289:in `find_spec_for_exe': can't find gem bundler (>= 0.a) with executable bundle (Gem::GemNotFoundException)
    from /usr/lib/ruby/2.5.0/rubygems.rb:308:in `activate_bin_path'
    from /srv/myuser/.gem/ruby/2.5.0/bin/bundle:23:in `<main>'

I've added /srv/myuser/.gem/ruby/2.5.0/bin to my path so I was able to install gems.

the gem env shows

RubyGems Environment:
  - RUBYGEMS VERSION: 2.7.7
  - RUBY VERSION: 2.5.1 (2018-03-29 patchlevel 57) [x86_64-linux]
  - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/2.5.0
  - USER INSTALLATION DIRECTORY: /srv/myuser/.gem/ruby/2.5.0
  - RUBY EXECUTABLE: /usr/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/bin
  - SPEC CACHE DIRECTORY: /srv/myuser/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /etc
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /usr/lib/ruby/gems/2.5.0
     - /srv/myuser/.gem/ruby/2.5.0
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - "gem" => "--user-install"
  - REMOTE SOURCES:
     - https://rubygems.org/
  - SHELL PATH:
     - /usr/local/sbin
     - /usr/local/bin
     - /usr/bin

gem list shows the installed gems. I can also find bundle when I perform:

ls -ltrah /srv/myuser/.gem/ruby/2.5.0/bin

I've also tried to install bundler but that didn't also help. What am I doing wrong?

gem which bundle is showing nothing.gem spec bundle is showing it.

Update: I tried to install bundler before running bundle but the same issue appears while:

gem list bundle shows

bundle (0.0.1)
bundler (2.0.1)

Answer 1

Bundler version 2 introduced a new feature to automatically use the version of Bundler specified in the Gemfile.lock of your project. Thus, if you have an existing Gemfile.lock with a line like this at the bottom

BUNDLED WITH
   1.17.3

Bundler will try to run with a Bundler version < 2.0. Since you just have Bundler 2.0.1 (and Rubygems >= 2.7.0) installed, this fails with this rather unhelpful error message.

To fix this, you could

• remove the lines from your Gemfile.lock and to use bundler 2.x everywhere from now on, or
• install a bundler 1.x version with gem install bundler -v '< 2.0' to use the appropriate version as specified by your Gemfile.lock.

More information about this can be found on the Bundler blog.