PreventBuildingOfEverything - SCons/scons GitHub Wiki
Suppose you have a big hierarchical tree of projects. If someone accidentally enters:
scons
it will build every project in that tree. If you want to ensure that they meant to build everything, add this to the SConstruct file:
# prevent accidental building of everything
Default(None)
If someone does want to build every project, they must do so explicitly by:
scons .