What is the system and compiler that you are using? Is it built with aliBuild? We have CI builds for CC7 and MacOS, and they were successful for the latests changes, so I have a suspicion that you have some unusual setup. Also, I have just pulled the latest O2 and QC versions on my CC7 machine and it still compiles.
I see:
4 errors generated.
But you have pasted only the last one. Could you please provide us with the full build log? It is usually misleading to look at the last error rather than the first.