I have a java application that is run from the command line. I have my logback.xml file configured to display all messages on the console.

In my logback.xml file, I have configured my logger like this:

 <logger name="com.ibm.sdk.codegen" level="${SDKGEN_LOGLEVEL:-INFO}">
   <appender-ref ref="STDOUT"/>
   <appender-ref ref="STDERR"/>
 </logger>

I want the default log level to be INFO, but I also would like to allow users to specify "-DSDKGEN_LOGLEVEL=DEBUG" as part of the java command to enable debug logging.

I'm following these instructions on how to do this, but I can't seem to get this to work.  I have some debugging code in my application that verifies the system property is being set as expected:

[INFO ] c.i.s.c.IBMDefaultCodegen: SDKGEN_LOGLEVEL=DEBUG this.class=IBMJavaCodegen

But logback-classic seems to not want to use that system property value.   What am i doing wrong? 

I'll attach my full logback.xml file to this issue for reference.