At least for the distributions I'm involved in there are no (automatic) "nightly" builds (of unreleased upstream software).
If a project builds distro packages in their CI, you can of course grab and install those. But you have to go hunting for it.
Flatpak developers sometimes/often(?) ship nightly, f.e. org.gnome.Calendar.Devel
so if you use flatpak this might be an option and should still be relatively safe (in terms of breakage).
@devrtz yeah I've seen a few nightly flatpaks. So if people want the latest they should follow the steps to build the development version to test and they are fully in control of the process, not some community packager.
A newer server operated by the Mastodon gGmbH non-profit