Strange lockfile behaviour with bundle update/install and platform-specific gems

[nilsding]

Hey everyone,
I recently stumbled upon some weird behaviour with bundle update and bundle install and some platform-specific gem dependencies in a few of our projects. I successfully managed to track it down to the following:

• The pry gem, which has at least two gem versions: one for any platform (I'll call that one ruby from now on) and one for java
• That java platform version has an additional dependency on spoon, which has a dependency on ffi
• Any bundle command which modifies the Gemfile which is not bundle install (e.g. bundle update or bundle lock) adds the ffi dependency for the ruby platform.
• bundle install will correctly remove the ffi gem for the ruby platform from the Gemfile.lock, as it determined it's apparently not needed for that platform.

I have created a git repository with each step in its own commit to reproduce this behaviour: https://github.com/nilsding/bundler-lockfile-issue/commits/master.

---

Output of bundle env, if it's of any help:

Environment

Bundler             1.16.1
  Platforms         ruby, universal-java-1.8
Ruby                2.3.3p0 (2018-02-21 revision 56859) [java]
  Full Path         /Users/nilsding/.rvm/rubies/jruby-9.1.16.0/bin/jruby
  Config Dir        /Users/nilsding/.rvm/rubies/jruby-9.1.16.0/etc
RubyGems            2.6.14.1
  Gem Home          /Users/nilsding/.rvm/gems/jruby-9.1.16.0
  Gem Path          /Users/nilsding/.rvm/gems/jruby-9.1.16.0:/Users/nilsding/.rvm/gems/jruby-9.1.16.0@global
  User Path         /Users/nilsding/.gem/jruby/2.3.0
  Bin Dir           /Users/nilsding/.rvm/gems/jruby-9.1.16.0/bin
Tools
  Git               2.16.2
  RVM               1.29.3 (master)
  rbenv             not installed
  chruby            not installed
  rubygems-bundler  (1.4.4)

Bundler Build Metadata

Built At          2017-12-21
Git SHA           0034ef341
Released Version  true

Bundler settings

jobs
  Set for the current user (/Users/nilsding/.bundle/config): "8"
gem.test
  Set for the current user (/Users/nilsding/.bundle/config): "rspec"
gem.mit
  Set for the current user (/Users/nilsding/.bundle/config): false
gem.coc
  Set for the current user (/Users/nilsding/.bundle/config): true

Gemfile

Gemfile

source "https://rubygems.org"

gem "pry"
gem "empyrean", "= 0.1.1"

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    coderay (1.1.2)
    empyrean (0.1.1)
    ffi (1.9.23-java)
    method_source (0.9.0)
    pry (0.11.3)
      coderay (~> 1.1.0)
      method_source (~> 0.9.0)
    pry (0.11.3-java)
      coderay (~> 1.1.0)
      method_source (~> 0.9.0)
      spoon (~> 0.0)
    spoon (0.0.6)
      ffi

PLATFORMS
  java
  ruby

DEPENDENCIES
  empyrean (= 0.1.1)
  pry

BUNDLED WITH
   1.16.1

[segiddins]

Weird, on master even bundle install doesn't seem to be removing ffi.

Thanks so much for the amazing repro case.

[segiddins]

I think #6495 should fix this!

[nilsding]

@segiddins yes, #6495 indeed fixes this! No more unnecessary platform-specific gems on bundle lock or bundle updates 🎉