Try install homebrew on arm64 ubuntu

[zouchengli]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

lima@lima-ubuntu-lts:~$ ruby -v
ruby 2.6.10p210 (2022-04-12 revision 67958) [aarch64-linux]

Output of brew doctor

lima@lima-ubuntu-lts:~$ echo $PATH
/home/lima.linux/.rbenv/shims:/home/lima.linux/.rbenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/sbin:/sbin:/usr/sbin:/sbin:/usr/sbin:/sbin:/home/lima.linux/.rbenv/versions/2.6.10/bin/

Description of issue

lima@lima-ubuntu-lts:~$ ./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

Press RETURN/ENTER to continue or any other key to abort:
==> /usr/bin/sudo /bin/chown -R lima:lima /home/linuxbrew/.linuxbrew/Homebrew
==> Downloading and installing Homebrew...
HEAD is now at Homebrew/brew@aa2a77b Merge pull request Homebrew/brew#16010 from apainintheneck/improve-versioned-formula-names-performance
Error: No Homebrew ruby 2.6.10_1 available for aarch64 processors!
Error: Failed to install Homebrew Portable Ruby and cannot find another Ruby 2.6.10!
If there's no Homebrew Portable Ruby available for your processor:

install Ruby 2.6.10 with your system package manager (or rbenv/ruby-build)
make it first in your PATH
try again
Failed during: /home/linuxbrew/.linuxbrew/bin/brew update --force --quiet

[SMillerDev]

https://docs.brew.sh/Homebrew-on-Linux#arm-unsupported

[SMillerDev]

It's not impossible, but it is a lot of work that nobody is currently doing. So it's not as simple as just bottling things.

For starters, Linux on ARM is not a platform that GitHub Actions (where Homebrews CI runs) supports. So you can write the code, but without a way to validate it it'll be a hard sell to officially support.

[naikrovek]

ok that is a good reason that this platform & architecture combination are not supported. I can stand up some single-use virtual machines on my Mac for my own stuff, but obviously that will not scale.

[naikrovek]

I wonder if lack of support here is holding up the implementation of arm64 Linux GitHub Actions runners. They use Homebrew on the Intel Linux runner images... That would be kinda funny.

can cross-compilation be done on amd64 Linux runners, to get started? I haven't done cross-compilation in ... a while, so I don't know how easy or difficult this is, anymore. it used to be something of a pain.

[SMillerDev]

Homebrew never does cross compilation anymore since it only ever brought us problems. Builds are optimised for the hardware they were made on.

I'm sure GitHub would ship runners without brew if that was the limiting factor.

[naikrovek]

you're right. there was an announcement at GitHub Universe.

https://github.blog/changelog/2023-10-30-accelerate-your-ci-cd-with-arm-based-hosted-runners-in-github-actions/

[ZhongRuoyu]

What you encountered was likely an issue running brew update-report at the end of brew update. When portable-ruby is unavailable, brew tries to find a working ruby from HOMEBREW_PATH ¹, the unfiltered PATH from the environment ². However, when brew is recursively invoked as a subprocess of itself, the already-filtered PATH from the parent brew process becomes the HOMEBREW_PATH in the subprocess. Having lost the original, unfiltered PATH information, brew update-report, run as a subprocess of brew ³, failed to find a working ruby, although it should be on PATH in the outside environment.

While running brew on aach64 Linux is still unsupported at the moment, you are welcome to make pull requests to improve the current situation. Or, if you just want to get it work for now, maybe try doing this somewhere in your modified installer script: ZhongRuoyu/homebrew-aarch64-linux@dcd91dc. By linking the rbenv-installed Ruby to where portable-ruby is expected, this effectively tricks brew by pretending that a portable-ruby is available. (This is not supported, so it can break anytime in the future.) If you do that, you may also want to remove rbenv's shims (~/.rbenv/shims) from your PATH, since brew cleanup may consider the "portable-ruby" unnecessary and proceed to remove it. (Try brew cleanup --dry-run to see it yourself.)

Footnotes

1. https://github.com/Homebrew/brew/blob/1f80e82dd72fce6642e4ea360f7a1feef5d78470/Library/Homebrew/utils/ruby.sh#L62 ↩

2. https://github.com/Homebrew/brew/blob/1f80e82dd72fce6642e4ea360f7a1feef5d78470/bin/brew#L152-L168 ↩

3. https://github.com/Homebrew/brew/blob/1f80e82dd72fce6642e4ea360f7a1feef5d78470/Library/Homebrew/cmd/update.sh#L896 ↩