Following hot on the heels of v4.2.1 is the latest release, v4.2.2. This is a bugfix release:

  • Fix a couple of bugs when updating Coordinates objects on the mesh
  • Fix a bug in FCI: missed the last point in Z for corner displacements
  • Fix location not being set correctly in LaplaceXZ
  • Fix some bugs in finite volume methods:
    • Wrong region used in loop
    • Metric component indexed at wrong location
    • Use field-aligned field if necessary
  • Fix wall-time limit not triggering on all processes
  • Link against libdl if needed for backtrace
  • Provide version numbering for Hypnotoad
  • Small improvements to testing frameworks
  • Various warning fixes

See for more details. You can download the source tarball from

Note: if you download the source code tarball from GitHub, please download the file BOUT++-v4.2.2.tar.gz rather than the GitHub generated tarballs. This is because the GitHub tarball does not include the submodules.