How do I fix the Laravel error: Your requirements could not be resolved to an installable set of packages

The Problem

When creating a Laravel project on Linux, you may get the error Your requirements could not be resolved to an installable set of packages.

This error could be caused by any number of missing dependencies, for example, you can get an error such as:

  - Root composer.json requires laravel/pint ^1.0 -> satisfiable by laravel/pint[v1.0.0, v1.1.0, v1.1.1].
  - laravel/pint[v1.0.0, ..., v1.1.1] require ext-xml * -> it is missing from your system. Install or enable PHP's xml extension.

The important message here is the second line — that ext-xml is missing from your system. This is a system-level omission, not a PHP error.

The Solution

This error has a simple solution. On Debian-based systems, install the missing dependency with apt-get. (On RedHat-based systems use yum.)

For example:

apt-get update
apt-get install php-xml
apt-get install php-curl

If you don’t have root privileges, prefix the commands with sudo.