If you've just tried to install Statamic's installer (composer global require statamic/cli ) and encountered an error that includes the phrase "Your requirements could not be resolved to an installable set of packages", thankfully the fix is probably simple. We wish errors gave you a better idea what to do next, but here we are.
Update Global Composer Dependencies
The most common reason for this issue is that your global Composer dependencies are out of date and whatever you're trying to install needs a newer version of package. You can update your global dependencies by running the following command, and then try whatever you were just doing one more time.
composer global updatePopping the Hood
If that doesn't resolve the issue, you may need to look at your list of global dependencies for clues. You may have a package that requires an older version of PHP or another dependency. This might take a little Googling , trial and error (remove a line and run composer global update and try again), or brute force, but will almost definitely result in finding the problem. Eventually. We're sorry it has come to this.
You can find where the global composer.json config file is by running the following command and looking at the [home] line.
composer config --list --globalIf you're on MacOS, that file will be at ~/.composer/composer.json
