The nightly channel

The nightly channel is a published TOML file describing successful builds of the master branch of forc and fuel-core for the day. These builds are released in the sway-nightly-binaries repository and the workflows in that repo start building them every day at 00:00 UTC.

The nightly channel within fuelup is updated by a scheduled GitHub workflow that runs every day at 01:00 UTC, after builds have finished. Note that nightlies might fail to build, in which case it is possible that the nightly toolchain may not be available for that day.

You should use nightly if you want the latest changes to master that have not been officially released yet. Keep in mind that compatibility between forc and fuel-core is not guaranteed here, and you should expect unstable features to break.