WiredTiger has an Evergreen job that measures Cyclomatic Code complexity using the uses the Mextrix++ tool.

The Evergreen job installs Metrix++ into the `src` directory. Unfortunately, this means that the complexity measurements include the Metrix++ source code as well as the WiredTiger source code, thus giving incorrect summary statistics (note that statistics on  individual files are correct). This problem is clear in the logs (eg https://evergreen.mongodb.com/task/wiredtiger_code_statistics_cyclomatic_complexity_da48c1b3a1a7a2bf0334ce78f5c53bc9ff7b0489_21_07_16_17_16_30 ).

The fix is to ensure that the install of Metrix++ is not into the `src' directory.