The current version of SFML downloaded with Brew (2.5.1) is not compatible with M1 chips and we need to upgrade the installation instructions to account for this.
Some more notes, you can get it working by downloading the most up to date version (3.0.0) and changing the cmake file to be
set(SFML_DIR "/SFML.framework/Resources/CMake")
find_package(SFML 3.0 COMPONENTS Window System Graphics Audio REQUIRED)
set(SFML_LIBS SFML::Window SFML::System SFML::Graphics SFML::Audio)
but some of the function signatures have changed and this will throw other errors
Feature
The current version of SFML downloaded with Brew (2.5.1) is not compatible with M1 chips and we need to upgrade the installation instructions to account for this.