Certain environment variables can impact the Directory Proxy Server in unexpected ways. This is particularly true for environment variables that are used by the underlying operating system to control how it uses non-default libraries.
For this reason, the Directory Proxy Server explicitly overrides the values of key environment variables like PATH, LD_LIBRARY_PATH, and LD_PRELOAD to ensure that something set in the environments that are used to start the server does not inadvertently impact its behavior.
If there is a legitimate need to edit any of these environment variables, the values of those variables should be set by manually editing the set_environment_vars function of the lib/_script-util.sh script. You will need to stop (bin/stop-server) and re-start (bin/start-server) the server for the change to take effect.