Setting SCYLLA_DBUILD_SO_DIR doesn't set LD_LIBRARY_PATH for the scylla process

[tgrabiec]

scylladb/scylla-dtest/docs/working-with-dbuild.md advertises that it's possible to run dtest with scylla built in a different environment, by setting SCYLLA_DBUILD_SO_DIR.

But ccm doesn't set LD_LIBRARY_PATH for the scylla process based on SCYLLA_DBUILD_SO_DIR, so scylla fails to start with an error like this:

/home/tgrabiec/.dtest/dtest-tc5khwa8/test/node1/bin/scylla: error while loading shared libraries: libboost_program_options.so.1.83.0: cannot open shared object file: No such file or directory

[fruch]

we do set it:

scylla-ccm/ccmlib/scylla_node.py

Line 1159 in 06ae5d4

self._launch_env = self._get_environ(LD_LIBRARY_PATH=dbuild_so_dir)

maybe the nodetool functions doesn't follow this....

it would help if you would have supplied a full backtrace of the failure