Installer failed until I installed the erb gem

[mister-walter]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

HOMEBREW_VERSION: 4.4.4
ORIGIN: https://github.com/Homebrew/brew
HEAD: 824efa8836dc226aa92dbbf7404c1b4a66707cca
Last commit: 15 hours ago
Core tap JSON: 05 Nov 00:20 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: :0
HOMEBREW_MAKE_JOBS: 16
Homebrew Ruby: 3.3.5 => /usr/bin/ruby
CPU: 16-core 64-bit zen3
Clang: 18.1.8
Git: 2.47.0 => /bin/git
Curl: 8.10.1 => /bin/curl
Kernel: Linux 6.11.6-arch1-1 x86_64 GNU/Linux
OS: Arch Linux
Host glibc: 2.40
/usr/bin/gcc: 14.2.1
/usr/bin/ruby: 3.3.5
glibc: N/A
gcc@11: N/A
gcc: N/A
xorg: N/A

Output of brew doctor

Your system is ready to brew.

Description of issue

On Arch Linux running Ruby 3.3.5, the installer failed until I manually installed the erb gem (I used pacman in my case: pacman -S ruby-erb).

Output of installer prior to installing ruby-erb:

$ /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
==> Checking for `sudo` access (which may request your password)...
==> This script will install:
/home/linuxbrew/.linuxbrew/bin/brew
/home/linuxbrew/.linuxbrew/share/doc/homebrew
/home/linuxbrew/.linuxbrew/share/man/man1/brew.1
/home/linuxbrew/.linuxbrew/share/zsh/site-functions/_brew
/home/linuxbrew/.linuxbrew/etc/bash_completion.d/brew
/home/linuxbrew/.linuxbrew/Homebrew
==> The following new directories will be created:
/home/linuxbrew/.linuxbrew/bin
/home/linuxbrew/.linuxbrew/etc
/home/linuxbrew/.linuxbrew/include
/home/linuxbrew/.linuxbrew/lib
/home/linuxbrew/.linuxbrew/sbin
/home/linuxbrew/.linuxbrew/share
/home/linuxbrew/.linuxbrew/var
/home/linuxbrew/.linuxbrew/opt
/home/linuxbrew/.linuxbrew/share/zsh
/home/linuxbrew/.linuxbrew/share/zsh/site-functions
/home/linuxbrew/.linuxbrew/var/homebrew
/home/linuxbrew/.linuxbrew/var/homebrew/linked
/home/linuxbrew/.linuxbrew/Cellar
/home/linuxbrew/.linuxbrew/Caskroom
/home/linuxbrew/.linuxbrew/Frameworks

Press RETURN/ENTER to continue or any other key to abort:
==> /usr/bin/sudo /usr/bin/install -d -o drew -g drew -m 0755 /home/linuxbrew/.linuxbrew
==> /usr/bin/sudo /bin/mkdir -p /home/linuxbrew/.linuxbrew/bin /home/linuxbrew/.linuxbrew/etc /home/linuxbrew/.linuxbrew/include /home/linuxbrew/.linuxbrew/lib /home/linuxbrew/.linuxbrew/sbin /home/linuxbrew/.linuxbrew/share /home/linuxbrew/.linuxbrew/var /home/linuxbrew/.linuxbrew/opt /home/linuxbrew/.linuxbrew/share/zsh /home/linuxbrew/.linuxbrew/share/zsh/site-functions /home/linuxbrew/.linuxbrew/var/homebrew /home/linuxbrew/.linuxbrew/var/homebrew/linked /home/linuxbrew/.linuxbrew/Cellar /home/linuxbrew/.linuxbrew/Caskroom /home/linuxbrew/.linuxbrew/Frameworks
==> /usr/bin/sudo /bin/chmod ug=rwx /home/linuxbrew/.linuxbrew/bin /home/linuxbrew/.linuxbrew/etc /home/linuxbrew/.linuxbrew/include /home/linuxbrew/.linuxbrew/lib /home/linuxbrew/.linuxbrew/sbin /home/linuxbrew/.linuxbrew/share /home/linuxbrew/.linuxbrew/var /home/linuxbrew/.linuxbrew/opt /home/linuxbrew/.linuxbrew/share/zsh /home/linuxbrew/.linuxbrew/share/zsh/site-functions /home/linuxbrew/.linuxbrew/var/homebrew /home/linuxbrew/.linuxbrew/var/homebrew/linked /home/linuxbrew/.linuxbrew/Cellar /home/linuxbrew/.linuxbrew/Caskroom /home/linuxbrew/.linuxbrew/Frameworks
==> /usr/bin/sudo /bin/chmod go-w /home/linuxbrew/.linuxbrew/share/zsh /home/linuxbrew/.linuxbrew/share/zsh/site-functions
==> /usr/bin/sudo /bin/chown drew /home/linuxbrew/.linuxbrew/bin /home/linuxbrew/.linuxbrew/etc /home/linuxbrew/.linuxbrew/include /home/linuxbrew/.linuxbrew/lib /home/linuxbrew/.linuxbrew/sbin /home/linuxbrew/.linuxbrew/share /home/linuxbrew/.linuxbrew/var /home/linuxbrew/.linuxbrew/opt /home/linuxbrew/.linuxbrew/share/zsh /home/linuxbrew/.linuxbrew/share/zsh/site-functions /home/linuxbrew/.linuxbrew/var/homebrew /home/linuxbrew/.linuxbrew/var/homebrew/linked /home/linuxbrew/.linuxbrew/Cellar /home/linuxbrew/.linuxbrew/Caskroom /home/linuxbrew/.linuxbrew/Frameworks
==> /usr/bin/sudo /bin/chgrp drew /home/linuxbrew/.linuxbrew/bin /home/linuxbrew/.linuxbrew/etc /home/linuxbrew/.linuxbrew/include /home/linuxbrew/.linuxbrew/lib /home/linuxbrew/.linuxbrew/sbin /home/linuxbrew/.linuxbrew/share /home/linuxbrew/.linuxbrew/var /home/linuxbrew/.linuxbrew/opt /home/linuxbrew/.linuxbrew/share/zsh /home/linuxbrew/.linuxbrew/share/zsh/site-functions /home/linuxbrew/.linuxbrew/var/homebrew /home/linuxbrew/.linuxbrew/var/homebrew/linked /home/linuxbrew/.linuxbrew/Cellar /home/linuxbrew/.linuxbrew/Caskroom /home/linuxbrew/.linuxbrew/Frameworks
==> /usr/bin/sudo /bin/mkdir -p /home/linuxbrew/.linuxbrew/Homebrew
==> /usr/bin/sudo /bin/chown -R drew:drew /home/linuxbrew/.linuxbrew/Homebrew
==> Downloading and installing Homebrew...
remote: Enumerating objects: 285282, done.
remote: Counting objects: 100% (10025/10025), done.
remote: Compressing objects: 100% (439/439), done.
remote: Total 285282 (delta 9660), reused 9668 (delta 9583), pack-reused 275257 (from 1)
remote: Enumerating objects: 55, done.
remote: Counting objects: 100% (34/34), done.
remote: Total 55 (delta 33), reused 33 (delta 33), pack-reused 21 (from 1)
==> Updating Homebrew...
Error: cannot load such file -- erb
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/patch.rb:5:in `<top (required)>'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/software_spec.rb:13:in `<top (required)>'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/formula.rb:21:in `<top (required)>'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/descriptions.rb:4:in `<top (required)>'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/cmd/update-report.rb:9:in `<top (required)>'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
<internal:/usr/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/extend/kernel.rb:11:in `require?'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/commands.rb:37:in `valid_internal_cmd?'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb:65:in `<main>'
Failed during: /home/linuxbrew/.linuxbrew/bin/brew update --force --quiet

I don't recall needing to install this package in prior Homebrew installs, so not quite sure if this is something funky with my configuration or what. In any case, it's resolved now that I've installed ruby-erb.

[Szybet]

It's the same for me

[Bo98]

Homebrew generally could use any part of the Ruby standard library, i.e. anything listed as a "default gem" in https://stdgems.org/ which is clearly documented as "these gems are part of Ruby and you can always require them directly. You cannot remove them."

It seems Arch breaks this rule and doesn't ship the full set? We do have our own copy of Ruby that can be used as a fallback so we could perhaps update our Ruby detection to detect Arch Linux Ruby and mark it as broken.

[mister-walter]

It seems that Arch Linux ships the Ruby standard library in a separate package that the Ruby package optionally depends on: ruby-stdlib (it's really just a package that depends on all of the packages that are needed to pull in the Ruby stdlib gems). I think I was further confused by the fact that the Arch Linux wiki page for Ruby doesn't specifically call out that the stdlib isn't included by default - maybe if I have some time later I'll edit that page to add such a mention.

I would be happy with the fallback solution you suggest.