I have tested with several CMake projects and non-CMake projects to check for regression. For any port that had cmake and pathfix already in USES (unnecessarily, I might add), I have fixed to make sure there is no double substitution. Some ports I removed pathfix from altogether because they handled pkgconfig data in a different manner and pathfix was totally pointless then and now.
The only bug I have found is that pathfix must come after cmake in the USES list and I have fixed those cases as well.