It turns out that CMSSW defines "likely" and "unlikely" symbols in its own source code - XrdClOptimizers.hh redefines these, resulting in an error. Can you put them inside the XrdCl namespace? --- Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/issues/16 ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-DEV list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-DEV&A=1