The second release candidate for the upcoming 3.0.0 release is now
available. You can download a tarball (on the top right of the this page) or checkout the 3.0.0-rc2
tag via Git.
Please go and test, and report any problems that you encounter. The final release of 3.0.0 will likely happen by the end of the week if no major problems are reported.
DuMux 3.0.0 is a major version update. Backwards-compatibility with 2.12 could not be maintained.