- ### Problem
If you have a `version` in your config file (this feature was
introduced in #6817), then running any `bundle` command will
make Bundler re-exec and ultimately run the `bundle` binstub twice.
### Details
When the `bundle` binstub gets executed, a `require "bundler"` is
evaluated. RubyGems tries to require the `bundler.rb` file from
the right `bundler` gem (in the event where you have multiple
bundler versions in your system).
RubyGems will prioritize a bundler version based on a few
heurisitics.
b50c40c92a/lib/rubygems/bundler_version_finder.rb (L19-L21)
This prioritize logic doesn't take into account the bundler version
a user has specific in this config. So what happens is:
1. User execute the `bundle` binstub
2. `require 'bundler'` is evaluated.
3. RubyGems prioritize activating the bundler version specified
in the Gemfile.lock
4. The CLI starts, and [Auto switch kicks in](b50c40c92a/bundler/lib/bundler/cli.rb (L81)). Bundler detects that
user specifed a version in its config and the current Bundler
version doesn't match.
5. Bundler exit and re-exec with the right bundler version.
### Solution
This patch introduce two fixes. First, it reads the bundler config
file and check for the local config first and then the global
config. This is because the local has precedence over global.
Second, the prioritization takes into account the version in config
and let RubyGems activate the right version in order to prevent
re-exec moments later.
Finally, I also want to fix this problem because its a step toward
fixing https://github.com/ruby/rubygems/issues/8106. I'll open
a follow up patch to explain.
https://github.com/ruby/rubygems/commit/d6e0f43133
ace5b10de4