[ruby] Build with --enable-load-relative?

[Frederick888]

Output of brew config

HOMEBREW_VERSION: 4.3.9-38-g4bd3b93
ORIGIN: https://github.com/Homebrew/brew
HEAD: 4bd3b938c395f27f422f75afd8852d547c554961
Last commit: 32 minutes ago
Core tap HEAD: 1e79bbc53b983805795b475d63f9fcb820b059f9
Core tap last commit: 8 hours ago
Core tap JSON: 11 Jul 07:46 UTC
Core cask tap HEAD: c61f5273858917543690958865beeee6bc2a6763
Core cask tap last commit: 9 hours ago
Core cask tap JSON: 11 Jul 07:34 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_BAT_THEME: gruvbox-dark
HOMEBREW_CASK_OPTS: ["--appdir=~/Applications", "--fontdir=/Library/Fonts"]
HOMEBREW_EDITOR: nvim
HOMEBREW_GITHUB_API_TOKEN: set
HOMEBREW_MAKE_JOBS: 12
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.3.3 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.3.3/bin/ruby
CPU: dodeca-core 64-bit kabylake
Clang: 15.0.0 build 1500
Git: 2.45.2 => /usr/local/bin/git
Curl: 8.6.0 => /usr/bin/curl
macOS: 14.5-x86_64
CLT: 15.3.0.0.1.1708646388
Xcode: 15.4

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
  phantomjs

Warning: Some installed kegs have no formulae!
This means they were either deleted or installed manually.
You should find replacements for the following formulae:
  v8@3.15
  q

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  cowsay
  dog
  mysql@5.7
  neofetch
  openssl@1.1
  pam_yubico
  pnpm@8
  pyyaml
  terraform
  upx
  ykclient

Warning: You have the following deprecated, official taps tapped:
  Homebrew/homebrew-cask-fonts
Untap them with `brew untap`.

Warning: gettext files detected at a system prefix.
These files can cause compilation and link failures, especially if they
are compiled with improper architectures. Consider removing these files:
  /usr/local/lib/libgettextlib.dylib
  /usr/local/lib/libintl.dylib
  /usr/local/include/libintl.h
  /usr/local/lib/libgettextlib.dylib
  /usr/local/lib/libintl.dylib
  /usr/local/include/libintl.h

Warning: Symlinked Cellars can cause problems.
Your Homebrew Cellar is a symlink: /usr/local/Cellar
                which resolves to: /Users/<redacted>

The recommended Homebrew installations are either:
(A) Have Cellar be a real directory inside of your HOMEBREW_PREFIX
(B) Symlink "bin/brew" into your prefix, but don't symlink "Cellar".

Older installations of Homebrew may have created a symlinked Cellar, but this can
cause problems when two formulae install to locations that are mapped on top of each
other during the linking step.

Warning: You have unlinked kegs in your Cellar.
Leaving kegs unlinked can lead to build-trouble and cause formulae that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  moreutils

Warning: Broken symlinks were found. Remove them with `brew cleanup`:
  /usr/local/bin/com.docker.cli
  /usr/local/bin/docker-compose

Description of issue

I added /usr/local/opt/ruby/bin to my PATH, and have a few gem install --user-install'ed gems. This allows me to have a global default Ruby setup with a few gems like solargraph, neovim, etc. without having to reinstall them across patch version updates.

I also use a version manager (mise) for many projects. Now if there is a native gem in ~/.gem for the same Ruby major/minor version, I'll get a linked to incompatible libruby error requiring it, as ~/.gem bundles are linked to absolute path /usr/local/opt/ruby/lib/libruby.3.3.dylib. The same thing happens even if I install the same gem to mise gem path, as ~/.gem has a higher priority by default.

$ command -v ruby
/usr/local/opt/ruby/bin/ruby
$ ruby --version
ruby 3.3.4 (2024-07-09 revision be1089c8ec) [x86_64-darwin23]
$ mise shell ruby@3.3.4
$ command -v ruby
/Users/frederick/.local/share/mise/installs/ruby/3.3.4/bin/ruby
$ gem env gempath
/Users/frederick/.gem/ruby/3.3.0:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/gems/3.3.0


$ otool -L ~/.gem/ruby/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle
/Users/frederick/.gem/ruby/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle:
        /usr/local/opt/ruby/lib/libruby.3.3.dylib (compatibility version 3.3.0, current version 3.3.4)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1345.120.2)
$ otool -L ~/.local/share/mise/installs/ruby/3.3.4/lib/ruby/gems/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle
/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/gems/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle:
        /Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/libruby.3.3.dylib (compatibility version 3.3.0, current version 3.3.4)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1345.120.2)

$ ruby -e 'require "msgpack"'
<internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:136:in `require': linked to incompatible /usr/local/Cellar/ruby/3.3.4/lib/libruby.3.3.dylib - /Users/frederick/.gem/ruby/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle (LoadError)
        from <internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:136:in `require'
        from /Users/frederick/.gem/ruby/3.3.0/gems/msgpack-1.7.2/lib/msgpack.rb:7:in `<top (required)>'
        from <internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:141:in `require'
        from <internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:141:in `rescue in require'
        from <internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:135:in `require'
        from -e:1:in `<main>'
<internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:136:in `require': cannot load such file -- msgpack (LoadError)
        from <internal:/Users/frederick/.local/share/mise/installs/ruby/3.3.4/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:136:in `require'
        from -e:1:in `<main>'

I can fix this issue by changing the /usr/local/opt/ruby/lib/libruby.3.3.dylib to @executable_path/../lib/libruby.3.3.dylib:

$ install_name_tool -change '/usr/local/opt/ruby/lib/libruby.3.3.dylib' '@executable_path/../lib/libruby.3.3.dylib' ~/.gem/ruby/3.3.0/gems/msgpack-1.7.2/lib/msgpack/msgpack.bundle
$ ruby -e 'require "msgpack"'
# ok

$ mise shell --unset ruby@3.3.4
$ ruby -e 'require "msgpack"'
# ok

Now there's actually a flag to do this by default: --enable-load-relative. It seems to be a little problematic in the past but looks alright now. We'll also need to skip relocation (how?), which overwrites libruby's install name:

==> Changing dylib ID of /usr/local/Cellar/ruby/3.3.4/lib/libruby.3.3.dylib
  from @executable_path/../lib/libruby.3.3.dylib
    to /usr/local/opt/ruby/lib/libruby.3.3.dylib

As I'm not the best person to ask about these stuff, I'm wondering if it makes sense to do this change, or there are any other issues I'm not aware of?

[SMillerDev]

It seems to be a little rbenv/ruby-build#1760 in the past but looks alright now.

That doesn't sound good

We'll also need to skip relocation (how?), which overwrites libruby's install name:

That will make life much worse for a bunch of people that don't install in the default location. I don't think that's worth it.

[Frederick888]

We'll also need to skip relocation (how?), which overwrites libruby's install name:

That will make life much worse for a bunch of people that don't install in the default location. I don't think that's worth it.

Is libruby not always located in $(dirname /path/to/bin/ruby)/../lib/?