Predefined Constant PHP_BINARY is an empty string

[Repox]

Not sure if this is a bug or intended, but I was using a CLI package that referenced the PHP_BINARY predefined constant - not the environment variable.

Most of the other predefined constants are available, but not this one.

Is this intended?

To add, the "known issues" touch the subject with Composer Scripts Referencing @php
suggesting the idea that overwriting /usr/local/bin/php with a custom Bash script.

This probably works, but it causes issues - for example a package like Laravels Horizon.

While the actual implementation (in this specific case) still wouldn't work if PHP_BINARY is set to something like /usr/local/bin/frankenphp php-cli, it would be fixable (with the aforementioned Bash script) if PHP_BINARY would point to /usr/local/bin/php. But pointing to another executable than the one actually running the script, makes PHP_BINARY less reliable as a constant than what is intended.

A quick search through some repositories on GitHub suggests that other packages as well, rely on this constant.

[AlliBalliBaba]

I guess the best solution here would be to just support -d and set the constant to /usr/local/bin/frankenphp php-cli. Tough it's a bit unfortuante that the cli sapi currently cannot be called directly.