https://github.com/rubygems/rubygems/commit/076aba8b1c

We have some places that already use `bundle config auto_install true`,
ie:

https://github.com/technicalpickles/rubygems/blob/7a144f3374f6a400cc9832f072dc1fc0bca8c724/bundler/lib/bundler/cli.rb#L11

This applies the same logic (copy and pasted) to happen when you
`require "bundler/setup"`.

https://github.com/rubygems/rubygems/commit/bb3c922341

Previous attempt to use a full path when the running version is
different than the one that would be activated by default are different
was not correct.

This is because if this error happens in a `bundle exec` context, the
`Gem.loaded_specs` is cleared because we're in an exec'd process, so
will be always using a full path in these cases.

This alternative approach should do what I was expecting.

https://github.com/rubygems/rubygems/commit/e0bb8bf51b

This problem is quite specific to our dev environment, but I guess the
fix could be handy for other situations.

After merging a change to treat default gems as regular gems, I get this
when trying to run `rubocop` on our repo:

```
$ bin/rubocop  --only Performance/RegexpMatch
Could not find json-2.6.3 in locally installed gems
Run `bundle install --gemfile /Users/deivid/code/rubygems/rubygems/tool/bundler/lint_gems.rb` to install missing gems.
```

However, when running the suggested command, nothing changes and I still
get the same error:

```
$ bundle install --gemfile /Users/deivid/code/rubygems/rubygems/tool/bundler/lint_gems.rb
Using ast 2.4.2
Using bundler 2.4.10
Using json 2.6.3
Using parallel 1.23.0
Using racc 1.7.1
Using parser 3.2.2.3
Using rainbow 3.1.1
Using regexp_parser 2.8.1
Using rexml 3.2.5
Using rubocop-ast 1.29.0
Using ruby-progressbar 1.13.0
Using unicode-display_width 2.4.2
Using rubocop 1.52.1
Using rubocop-performance 1.14.2
Bundle complete! 2 Gemfile dependencies, 14 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

$ bin/rubocop  --only Performance/RegexpMatch
Could not find json-2.6.3 in locally installed gems
Run `bundle install --gemfile /Users/deivid/code/rubygems/rubygems/tool/bundler/lint_gems.rb` to install missing gems.
```

The problem is that our `bin/rubocop` script uses the development
version of Bundler (which has the change causing the problem), but the
advice recommands the default version of Bundler, which does not yet
have the change.

This commit changes the advice to recommend to use the same version of
Bundler that run into the problem in the first place.

So in the above situation you now get:

```
$ bin/rubocop  --only Performance/RegexpMatch
Could not find json-2.6.3 in locally installed gems
Run `/Users/deivid/code/rubygems/rubygems/bundler/exe/bundle install --gemfile /Users/deivid/code/rubygems/rubygems/tool/bundler/lint_gems.rb` to install missing gems.
```

And running that fixes the problem:

```
$ /Users/deivid//rubygems/rubygems/bundler/exe/bundle install --gemfile /Users/deivid/code/rubygems/rubygems/tool/bundler/lint_gems.rb
Fetching gem metadata from https://rubygems.org/.........
Fetching json 2.6.3
Installing json 2.6.3 with native extensions
Bundle complete! 2 Gemfile dependencies, 14 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.
```

https://github.com/rubygems/rubygems/commit/10a9588c6d

If the original `BUNDLE_GEMFILE` is different from the default, then the
suggestion wouldn't work as is.

Before:

```
$ util/rubocop
Could not find rubocop-1.30.1 in locally installed gems
Run `bundle install` to install missing gems.

$  rubygems git:(better-cmd-suggestion) ✗ bundle install
Could not locate Gemfile
```

After:

```
$ util/rubocop
Could not find rubocop-1.30.1 in locally installed gems
Run `bundle install --gemfile /path/to/rubygems/bundler/tool/bundler/lint_gems.rb` to install missing gems.

$ bundle install --gemfile /path/to/rubygems/bundler/tool/bundler/lint_gems.rb
Fetching gem metadata from https://rubygems.org/.........
Using ast 2.4.2
Using bundler 2.4.7
Using parser 3.1.2.0
Using rainbow 3.1.1
Using parallel 1.22.1
Using regexp_parser 2.5.0
Using rubocop-ast 1.18.0
Using rexml 3.2.5
Using ruby-progressbar 1.11.0
Using unicode-display_width 2.1.0
Fetching rubocop 1.30.1
Installing rubocop 1.30.1
Using rubocop-performance 1.14.2
Bundle complete! 2 Gemfile dependencies, 12 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

$ util/rubocop
Inspecting 345 files
.........................................................................................................................................................................................................................................................................................................................................................

345 files inspected, no offenses detected
```

https://github.com/rubygems/rubygems/commit/bf1320d805

Bundler formatters already take care of this.

https://github.com/rubygems/rubygems/commit/c24415fdd5

  Features:
    - Add caller information to some deprecation messages to make them easier to fix [#7361](https://github.com/bundler/bundler/pull/7361)
    - Reconcile `bundle cache` vs `bundle package` everywhere. Now in docs, CLI help and everywhere else `bundle cache` is the preferred version and `bundle package` remains as an alias [#7389](https://github.com/bundler/bundler/pull/7389)
    - Display some basic `bundler` documentation together with ruby's RDoc based documentation [#7394](https://github.com/bundler/bundler/pull/7394)

  Bugfixes:
    - Fix typos deprecation message and upgrading docs [#7374](https://github.com/bundler/bundler/pull/7374)
    - Deprecation warnings about `taint` usage on ruby 2.7 [#7385](https://github.com/bundler/bundler/pull/7385)
    - Fix `--help` flag not correctly delegating to `man` when used with command aliases [#7388](https://github.com/bundler/bundler/pull/7388)
    - `bundle add` should cache newly added gems if an application cache exists [#7393](https://github.com/bundler/bundler/pull/7393)
    - Stop using an insecure folder as a "fallback home" when user home is not defined [#7416](https://github.com/bundler/bundler/pull/7416)
    - Fix `bundler/inline` warning about `Bundler.root` redefinition [#7417](https://github.com/bundler/bundler/pull/7417)

  Pick from 8dd59e3ba97eb80a599f8149f31bf40773b69dc0

  https://github.com/bundler/bundler/commit/a53709556b95a914e874b22ed2116a46b0528852

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e