You may need to recompile the GNAT library in various debugging or
experimentation contexts. The GNAT distribution provides a project
file called libada.gpr to do that; it can be found in the
directory containing the GNAT library. The location of this directory
depends on the way the GNAT environment has been installed and can be
determined by means of the command:
$ gnatls -v
The last entry in the source search path usually contains the
GNAT library (the adainclude directory).
This project file contains its own documentation and, in particular, the set of instructions needed to rebuild a new library and to use it.
Note that rebuilding the GNAT Run-Time is only recommended for temporary experiments or debugging and is not supported for other purposes.