When using project files, a usable version of the library is created in the
directory specified by the Library_Dir attribute of the library
project file. Thus no further action is needed in order to make use of
the libraries that are built as part of the general application build.
You may want to install a library in a context different from where the library
is built. This situation arises with third party suppliers, who may want
to distribute a library in binary form where the user is not expected to be
able to recompile the library. The simplest option in this case is to provide
a project file slightly different from the one used to build the library, by
using the externally_built attribute. Using Library Projects
Another option is to use gprinstall to install the library in a different context than the build location. A project to use this library is generated automatically by gprinstall which also copy, in the install location, the minimum set of sources needed to use the library. Installation