Using the env parameter "Parent_Stream" for the "Stream selector" when making recommended baseline results in an error:
cleartool chstream -rec -def ${Parent_Stream}
cleartool: Error: Unable to determine VOB for pathname ".".
cleartool: Error: Unable to find stream "${Parent_Stream}".

Fix to expand the env variable for the make recommended baseline command:
UcmMakeBaseline.java, about line 305:
was: recommendBaseline(clearTool, ucm.getStream());
now: recommendBaseline(clearTool, Util.replaceMacro(ucm.getStream(), variableResolver) );