seeing error dyld: Symbol not found: ___ulock_wait2 on Mac OS 10.15 x86_64

[AustinwLangley]

I have an older mac running Mac OS Catalina 10.15. Installed ruby on rails 8.0.2 just fine, created a test app, confirmed it worked when I spun it up on the rails server (bin/rails server).

I wanted to add the latest tailwind CSS version so I ran:

./bin/bundle add tailwindcss-rails
then
./bin/rails tailwindcss:install

When I run bin/dev I get the following error:

17:04:43 css.1  | dyld: Symbol not found: ___ulock_wait2
17:04:43 css.1  |   Referenced from: /Users/A/.rbenv/versions/3.3.5/lib/ruby/gems/3.3.0/gems/tailwindcss-ruby-4.1.4-x86_64-darwin/exe/x86_64-darwin/tailwindcss (which was built for Mac OS X 13.0)
17:04:43 css.1  |   Expected in: /usr/lib/libSystem.B.dylib
17:04:43 css.1  | 
17:04:43 css.1  | exited with code 0
17:04:43 system | sending SIGTERM to all processes
17:04:43 web.1  | - Gracefully stopping, waiting for requests to finish
17:04:43 web.1  | Exiting

I noticed Mac OS X 13.0 in the error, my computer is a late-2012 model mac, running Catalina and can't upgrade anymore. Is it possible to include exception handling for older macOS versions so that older macs can run the latest tailwindcss verson?

[flavorjones]

Hi, sorry you're having a problem, thanks for reporting it.

I think what you're seeing is an issue with the upstream binary CLI (from https://github.com/tailwindlabs/tailwindcss/releases) which is what tailwindcss-rails and tailwindcss-ruby use. Version 4 of tailwind ships binary executables built with bun, and there have been reports like this on some platforms and chipsets.

To make sure I'm making a correct conclusion, can you try downloading the darwin executable from https://github.com/tailwindlabs/tailwindcss/releases/download/v4.1.4/tailwindcss-macos-x64 and run it? My expectation is that you'll see the Symbol not found error, in which case you should report this upstream.

Does that make sense? Let me know if you have trouble with that or have other questions.

[flavorjones]

If I'm correct, you will either need to use tailwind v3 or install tailwind through npm. The README at https://github.com/flavorjones/tailwindcss-ruby should provide some help.

I'm going to close this, but if I'm not correct just drop a comment and I'm happy to reopen and chat more about it.