I think it's better if default logging would go to session:temp-directory instead of the basedir. The ant scripts are relative to the basedir and I like to keep those directories not globally writable.
I changed 2 lines in automation/appSolutions/appSolute/RTB/Base/RTBAutomationApi.cls
OUTPUT STREAM sLogStream TO VALUE(SUBSTITUTE("&1/adrtbapi_process.log", SESSION:TEMP-DIRECTORY)) APPEND.
OUTPUT STREAM sLogStream TO VALUE(SUBSTITUTE("&1/adrtbapi_process.log", SESSION:TEMP-DIRECTORY)).
Another change, on line 1571 add directory to error message
pcError = SUBSTITUTE("Error: Invalid base directory &2 for import analysis report. Cannot create report.~n&1", Err:GetMessage(1), pcReportBaseDir).