External Packages and UPS

Not all packages used by the experiment will be included in the release structure. External packages, such as CERNLIB or tcl/TK or gcc, for which we do not usually rebuild the code, are not located in the release structure. They are located somewhere else which is pointed to by the normal UPS environmental variable. We do not use CVS to track the source code of external packages. There is no restriction on where the environmental variable <product>_DIR points. If we need to rebuild external packages, we use their own makefiles, not the SoftRelTools makefiles.

In the SoftRelTools makefiles we use the UPS <product>_DIR environmental variables to pickup external package libraries and include areas necessary for building. These environmental variables may be defined through UPD dependencies, whereby we have declared the project to depend on a given version of an external package. The intent is that <product>_DIR is set when we setup the project, not via a separate ``setup $<$product$>$'' statement which might pickup the wrong version of the external product for the project.