Playing Widevine (DRM protected) videos on Chimera Linux

Widevine CDMs (Content Decryption Modules) are distributed as proprietary binaries compiled for glibc and won't run on musl systems, like Chimera Linux or the musl version of Void Linux.

On Chimera Linux, Firefox is configured by default to not prompt to download Widevine when needed like it normally will. You can override this in about:config but the plugin will just crash under musl.

Workaround

The easiest way to get around this seems to be to install a browser with Flatpak, which are compiled with glibc and ships with the environment they need, even on musl systems.

Annoyingly, while running an instance of musl Firefox, starting Firefox with flatpak run will not start a second Firefox process but instead open a new window of your musl Firefox. Firefox has a flag for that though: flatpak run org.mozilla.firefox --new-instance starts a new instance of Flatpak Firefox.