Unable to install gem on an Apple Silicon M1 Mac

[chrismanderson]

Describe the bug
I am unable to install this gem on an M1 Mac using either bundler or a direct gem install.

To reproduce
Run bundle install for Ruby application that contains this gem in its gemfile.

Expected behavior
The gem installs successfully.

Actual behavior
I receive build error messages and the gem does not build.

Logs

ERROR:  Error installing launchdarkly-server-sdk:
	ERROR: Failed to build gem native extension.

    current directory: /Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/llhttp-ffi-0.4.0/ext
/Users/chris/.rbenv/versions/3.0.2/bin/ruby -I/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0 -rrubygems /Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/rake-13.0.6/exe/rake RUBYARCHDIR\=/Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/extensions/arm64-darwin-21/3.0.0/llhttp-ffi-0.4.0 RUBYLIBDIR\=/Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/extensions/arm64-darwin-21/3.0.0/llhttp-ffi-0.4.0
rake aborted!
LoadError: dlopen(/Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/ffi-1.15.5/lib/ffi_c.bundle, 0x0009): tried: '/Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/ffi-1.15.5/lib/ffi_c.bundle' (mach-o file, but is an incompatible architecture (have 'x86_64', need 'arm64e')), '/usr/local/lib/ffi_c.bundle' (no such file), '/usr/lib/ffi_c.bundle' (no such file) - /Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/ffi-1.15.5/lib/ffi_c.bundle
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:160:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:160:in `rescue in require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:149:in `require'

Caused by:
LoadError: cannot load such file -- 3.0/ffi_c
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:160:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:160:in `rescue in require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:149:in `require'

Caused by:
LoadError: cannot load such file -- ffi-compiler/compile_task
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
<internal:/Users/chris/.rbenv/versions/3.0.2/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
(See full trace by running task with --trace)

rake failed, exit code 1

Gem files will remain installed in /Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/llhttp-ffi-0.4.0 for inspection.
Results logged to /Users/chris/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/extensions/arm64-darwin-21/3.0.0/llhttp-ffi-0.4.0/gem_make.out

SDK version
6.3.1

Language version, developer tools
Ruby 3.0.2, Rails 6.1.4.6

OS/platform
macOS 12.2.1 running on an Apple Silicon Mac.

Additional context
This fails both when doing a bundle install and when doing a manual gem install launchdarkly-server-sdk.

[eli-darkly]

This looks to me like it is a more basic issue with Ruby and the ffi gem on Mac— not with the LaunchDarkly SDK specifically. Have you looked at articles like https://betterprogramming.pub/ruby-on-apple-silicon-m1-macs-fb159849b2f5 or https://stackoverflow.com/questions/66644365/cocoapods-on-m1-apple-silicon-fails-with-ffi-wrong-architecture?

[eli-darkly]

I believe it's been a known issue for a long time that ffi and other Ruby gems relying on native extensions don't necessarily work right out of the box on MacOS; I've had to look up workarounds for how to install them correctly every time I set up a Ruby dev environment on any Mac, not just an M1 Mac. The LaunchDarkly SDK itself does not have any native components, but it does have a dependency on ffi and it looks to me like the error you're seeing there is specifically about ffi.

[crypt0leslie]

I agree with @eli-darkly, my laptop is also Apple Silicon M1 Mac, and can install launchdarkly-server-sdk via bundle add

[keelerm84]

Closing as ffi seems to compile without issue on the M1s now.