The abinit-fallbacks project is a package builder for the external libraries (on which Abinit relies) in development environments lacking these, on which the user/developer might "fall back" in order to build these libraries. You will find on the Web site of the project all the information on how to build and install fallbacks from source. The list of dependencies is mentioned below.
In versions of ABINIT prior to ABINIT 5.6, the external libraries were shipped with the sources, and managed by the build system. Then, from ABINIT 5.6 and up to ABINIT 8.10.3 these were automatically downloaded at configure time. This proved too difficult to maintain. Starting with ABINIT 9, external libraries are no longer managed by the ABINIT build system. It is supposed that these libraries are already available at compile time in development environments. The abinit-fallbacks package builder can help to achieve proper set up of the external dependencies.
