2.7. Applying patches
It is easy to stay current with the most recent LAMMPS patch releases if you use Git or SVN to track LAMMPS development. Instructions for how to stay current are on the Install git and Install svn doc pages.
If you prefer to download a tarball, as described on the Install git doc 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 and 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.
You should not apply patch files to a local Git or SVN repo of LAMMPS, only to an unpacked tarball. Use Git and SVN commands to update repo versions of LAMMPS.
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.
If you wish to edit/change a src file that is from a package, you should edit the version of the file inside the package sub-dir of src, then re-install the package. The version in the src dir is merely a copy and will be wiped out if you type “make package-update”.