Tailwindcli process suddenly exits

[itsbilolbek]

Describe the bug

Process exits unexpedtedly when it is supposed to run continuously.

To reproduce

My devenv.nix looks something like this:

{ pkgs, ...}:
{
  packages = [
    pkgs.tailwindcss_4
  ];

  processes = {
    tailwind.exec = ''
      tailwindcss \
        -i ./style.css \
        -o ./output.min.css \
        --watch \
        --minify
    '';
  };
}

I use this process to watch for tailwind class changes and immediately produce a minified file. When I run devenv up this process only runs once and exits. But if I run the same command on the command line it watches for changes.

Version

devenv 2.2.0 (x86_64-linux)
I don't use flakes, just devenv.nix

[sandydoo]

Confirmed. There's an issue with how we wrap processes and provide stdin.

As a workaround, you can pass --watch=always to tailwindcss.