2.7. Applying patches

It is easy to stay current with the most recent LAMMPS patch releases if you use git to track the LAMMPS development. Instructions for how to stay current are on the Download the LAMMPS source with git page.

If you prefer to download a tarball, as described on the tarball download page, you can stay current by downloading “patch files” when new patch releases are made. A link to a patch file is posted on the bug fixes and new feature page of the LAMMPS website, along with a list of changed files and details about what is in the new patch release. This page explains how to apply the patch file to your local LAMMPS directory.

Note

You should not apply patch files to a local git checkout of LAMMPS, only to an unpacked tarball. Use git commands to update such a version of the LAMMPS source code.

Here are the steps to apply a patch file. Note that if your version of LAMMPS is several patch releases behind, you need to apply all the intervening patch files in succession to bring your version of LAMMPS up to date.

  • Download the patch file. You may have to shift-click in your browser to download the file instead of display it. Patch files have names like patch.12Dec16.

  • Put the patch file in your top-level LAMMPS directory, where the LICENSE and README files are.

  • Apply the patch by typing the following command from your top-level LAMMPS directory, where the redirected file is the name of the patch file.

    $ patch -bp1 < patch.12Dec16
    
  • A list of updated files print out to the screen. The -b switch creates backup files of your originals (e.g. src/force.cpp.orig), so you can manually undo the patch if something goes wrong.

  • Type the following from the src directory, to enforce consistency between the src and package directories. This is OK to do even if you don’t use one or more packages. If you are applying several patches successively, you only need to type this once at the end. The purge command removes deprecated src files if any were removed by the patch from package sub-directories.

    $ make purge
    $ make package-update
    
  • Re-build LAMMPS via the “make” command.

Warning

If you wish to edit/change a source file that is part of a package, you should edit the version of the file inside the package folder in src, and then re-install or update the package. The version in the src directory is merely a copy and will be wiped out when you type “make package-update”.