In order to actually build the contents of the bin directory, you need to specify ‘bin’ as a target on the build commandline:
./scons.py -j2 mode=release bin
This will indeed place just symlinks in the Rosetta bin directory, but they should be linked to the actual versions of the binaries.
The other thing to be aware of is that the Rosetta bin directory will not be in your path by default. Instead, you’ll need to give the path to the binaries instead. Something like “/home/siaseb/Rosetta/main/source/bin/AbinitioRelax.default.linuxgccrelease” rather than just “AbinitioRelax.default.linuxgccrelease” (Change paths as appropriate.)