curl fails to upgrade on 9.1-RELEASE-p3 but succeeds on 8.3

[Dewayne]

The quick way to build the latest curl on FreeBSD 9.1 is to pass DISABLE_VULNERABILITIES to the make command.  Its probably a good
idea to leave your audit db alone, for this task.

cd /usr/ports/ftp/curl && make -DDISABLE_VULNERABILITIES

For portmaster this takes the form of 
portmaster  -m -DDISABLE_VULNERABILITIES ftp/curl

I'm unfamiliar with portupgrade.
Regards, Dewayne