The behavior of the server shell scripts in unsetting LOG_DIR env var is unexplained

On the one hand we do a fine job explaining how the LOG_DIR env var will configure the location of the Liberty logs, (see: https://openliberty.io/docs/latest/log-trace-configuration.html#settings).

What we don't explain is that a LOG_DIR env var supplied in server.env can not be referenced as an environment variable. It is unset in https://github.com/OpenLiberty/open-liberty/blob/d4d2cad32f282fa48b0f9b8db36a234f32a96fa5/dev/com.ibm.ws.kernel.boot.ws-server/publish/bin/server#L580-L588 and the values are transferred to an X_LOG_DIR.

So if a user wants to use/reference their LOG_DIR value in some other context, they don't have an easy way of doing so.

Of course, they could consider using another approach like the bootstrap.properties in some use cases. But in this use case from StackOverflow, using SpringBoot application properties, this wouldn't be an option.

Is it doc'd that they could use X_LOG_DIR in this fashion?

Should this be explained or rationalized briefly?

Start with the log-trace configuration documentation and the server script at dev/com.ibm.ws.kernel.boot.ws-server/publish/bin/server, especially lines 580-588. Verify how LOG_DIR from server.env is transferred to X_LOG_DIR and review the linked Stack Overflow use case. Done means the documentation explains whether and how X_LOG_DIR can be referenced, or briefly rationalizes the behavior and alternatives.