Flarum can't be installed or upgraded if PHP 8 is installed.
$ composer update --no-install --with-all-dependencies
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.
Problem 1
- dflydev/fig-cookies[v2.0.1, ..., v2.0.3] require php ^7.2 -> your php version (8.0.0) does not satisfy that requirement.
- flarum/core v0.1.0-beta.15 requires dflydev/fig-cookies ^2.0.1 -> satisfiable by dflydev/fig-cookies[v2.0.1, v2.0.2, v2.0.3].
- Root composer.json requires flarum/core >=0.1.0-beta.15 <0.1.0-beta.16 -> satisfiable by flarum/core[v0.1.0-beta.15].
Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.
Currently, the only workaround is to run the command with the --ignore-platform-reqs flag.
