Issue with asset:precompile not processing calculated utility classes.

[antonysastre]

Using Rails 8.0.2, newly generated app with the --css tailwindcss option.

Locally in development everything works fine with an app/assets/tailwind/application.css with only the @import "tailwindcss"; directive from the installation. I can use all classes and the views are rendered properly when running the Procfile.dev defined servers (including the tailwindcss:watch).

But, when i push my app for deployment with Kamal i've stumbled upon issues when reaching the assets:precompile step.

At first it exited with an error not able to deploy the app. I was using the old @apply { ... } directive to create som custom classes such as '.input-select' to re-use on <select …> components. The error stated that it couldn't find px-3 which was one of the utility classes used in the directive. I deleted all this and just using classes in views now.

The assets:precompile step is now running successfully on the remote server, the app is running but the views only get styling on non-calculated utility classes i.e. shadow-lg, but calculated ones such as px-3, h-16 etc – they are simply not being part of the compiled css.

Any suggestions on what might I might be missing?

• Gemfile.lock

    tailwindcss-rails (4.2.3)
      railties (>= 7.0.0)
      tailwindcss-ruby (~> 4.0)
    tailwindcss-ruby (4.1.7)
    tailwindcss-ruby (4.1.7-aarch64-linux-gnu)
    tailwindcss-ruby (4.1.7-aarch64-linux-musl)
    tailwindcss-ruby (4.1.7-arm64-darwin)
    tailwindcss-ruby (4.1.7-x86_64-linux-gnu)
    tailwindcss-ruby (4.1.7-x86_64-linux-musl)