Using `brew bundle exec bundle install` fails during post install due to not finding asdf

[technicalpickles]

I've often had success with brew bundle to specify macOS dependencies, and then using brew bundle exec bundle install to make sure the build env has everything set in there. This is a way to make sure mysql2 gem finds the mysql libraries, for example. Bundle Install With Homebrew Magic Using Brew Bundle Exec does a really good job explaining this pattern.

I've had problems doing this since switching to asdf. I'm including the output from brew bundle exec bundle install at the bottom of this issue, which is conveniently already formatted for markdown 😁

Some details that might be relevant:

❯ asdf --version                                                                                                                                                                                                                                
v0.10.2

❯ asdf plugin list --urls | grep ruby
ruby                         https://github.com/asdf-vm/asdf-ruby.git

❯ asdf plugin list --refs | grep ruby
ruby                         master a1352b4

The workaround I've found is to run bundle install without brew bundle exec to make sure it succeeds.

Backtrace

Errno::ENOENT: No such file or directory - asdf
  /Users/josh.nichols/.asdf/plugins/ruby/rubygems-plugin/rubygems_plugin.rb:5:in ``'
  /Users/josh.nichols/.asdf/plugins/ruby/rubygems-plugin/rubygems_plugin.rb:5:in `install'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/installer.rb:89:in `block in run'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/process_lock.rb:12:in `block in lock'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/process_lock.rb:9:in `open'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/process_lock.rb:9:in `lock'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/installer.rb:71:in `run'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/installer.rb:23:in `install'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/cli/install.rb:60:in `run'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/cli.rb:253:in `block in install'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/settings.rb:131:in `temporary'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/cli.rb:252:in `install'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/vendor/thor/lib/thor/invocation.rb:127:in `invoke_command'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/vendor/thor/lib/thor.rb:392:in `dispatch'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/cli.rb:31:in `dispatch'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/vendor/thor/lib/thor/base.rb:485:in `start'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/cli.rb:25:in `start'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/exe/bundle:49:in `block in <top (required)>'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/lib/bundler/friendly_errors.rb:128:in `with_friendly_errors'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0/gems/bundler-2.2.29/exe/bundle:37:in `<top (required)>'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/bin/bundle:25:in `load'
  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/bin/bundle:25:in `<main>'

Environment

Bundler       2.2.29
  Platforms   ruby, arm64-darwin-21
Ruby          2.7.6p219 (2022-04-12 revision c9c2245c0a25176072e02db9254f0e0c84c805cd) [arm64-darwin21]
  Full Path   /Users/josh.nichols/.asdf/installs/ruby/2.7.6/bin/ruby
  Config Dir  /Users/josh.nichols/.asdf/installs/ruby/2.7.6/etc
RubyGems      3.3.19
  Gem Home    /Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0
  Gem Path    /Users/josh.nichols/.gem/ruby/2.7.0:/Users/josh.nichols/.asdf/installs/ruby/2.7.6/lib/ruby/gems/2.7.0
  User Home   /Users/josh.nichols
  User Path   /Users/josh.nichols/.gem/ruby/2.7.0
  Bin Dir     /Users/josh.nichols/.asdf/installs/ruby/2.7.6/bin
OpenSSL
  Compiled    OpenSSL 1.1.1n  15 Mar 2022
  Loaded      OpenSSL 1.1.1n  15 Mar 2022
  Cert File   /Users/josh.nichols/.asdf/installs/ruby/2.7.6/openssl/ssl/cert.pem
  Cert Dir    /Users/josh.nichols/.asdf/installs/ruby/2.7.6/openssl/ssl/certs
Tools
  Git         2.37.1
  RVM         not installed
  rbenv       not installed
  chruby      not installed

Bundler Build Metadata

Built At          2021-10-08
Git SHA           4440b035ef
Released Version  true

Bundler settings

force_ruby_platform
  Set for the current user (/Users/josh.nichols/.bundle/config): true
unset
  Set for the current user (/Users/josh.nichols/.bundle/config): "jobs"

[technicalpickles]

From brew bundle help:

brew bundle exec command:
    Run an external command in an isolated build environment based on the
Brewfile dependencies.

That would include an isolated env that doesn't have asdf on the path.

I think the simplest fix would be to check that asdf is on the path before calling it in rubygem_plugin.rb.

I don't know if there are any hints in the environment when something is brew bundle exec'd, but that would be another way to skip trying to do it. I ran brew bundle exec env to get a dump, and while there's tons of HOMEBREW_ variables, I don't see any that suggest it's part of a bundle.