There is a build server continuously building the latest tip of the development branch of Octave. The build server is running Hydra, which is based on the Nix functional package management system. This is the official continuous build system of the GNU Project. The Hydra build of Octave is currently maintained by User:Mtmiller.
Octave Job Overview
The octave-default jobset overview page is the main entry point to the Hydra build of Octave. It shows the status of the most recent builds ("evaluations" in Hydra terminology).
Latest Build Logs
The full build logs for the latest builds are available at the following links, for quick reference:
Snapshot Source Tarball
A nice product of the Hydra continuous build of Octave is that there is always a source snapshot available for download. This source snapshot is always built from the current tip of the development branch in whatever state it is in. Therefore, it may not compile or run properly and should definitely not be used for anything other than evaluation. This can be useful to evaluate the current state of Octave's development branch without needing to clone the Mercurial repository.
Another product of the Hydra continuous build is the code coverage report. The latest coverage report is always built from the current tip of the development branch. This report gives an analysis of the code coverage of the current Octave test suite. This can be used to find unexercised code paths and help improve the coverage of Octave's test suite.