Bug: Undefined constant CodeIgniter\CLI\STDERR #5006

PHP Version

8.5

CodeIgniter4 Version

4.7.4

CodeIgniter4 Installation Method

Git

Which operating systems have you tested for this bug?

macOS, Linux

Which server did you use?

cli-server (PHP built-in webserver)

Environment

development

Database

No response

What happened?

Running a command from a controller through command() ends in a fatal error when the command reports an error with CLI::error():

Error: Undefined constant "CodeIgniter\CLI\STDERR"

PHP defines STDIN, STDOUT and STDERR only in the CLI SAPI. Outside the CLI, CLI::init() defines a stand-in for STDOUT (php://output) but not for STDERR, and CLI::error() references STDERR both for its color check and for the write itself.

Steps to Reproduce

1. Add a route to a controller method that runs a command reporting an error, for example an unknown command name:

   public function index(): string
   {
       return (string) command('no:such-command');
   }

2. Serve the app with a web SAPI (php spark serve, Apache with mod_php, or PHP-FPM).

3. Request the route.

Expected Output

command() returns the error message as part of the command's output, the same way it returns output from CLI::write(), instead of the request ending in a fatal error.

Anything else?

Originally reported on CodeIgniter 4.1.3 with PHP 8.0.8, Apache 2.4.29 and Ubuntu 18.04.5, using a custom command that calls CLI::error(). The reporter worked around it by overriding CLI::error() to write through STDOUT when is_cli() is false.

Still reproducible on develop (b86f337). The same class of problem affects CLI::clearScreen() on Windows, which probes the STDOUT stand-in string for VT100 support, and SignalTrait::getProcessState(), which calls posix_isatty(STDIN).