NCover coverage widley differnt from UAT build to a Live build

Question

Using TeamCity running an MsBuild task for an MVC2 C# application, we successfully run 1561 XUNit tests in both the UAT and the Live builds but the NCover coverage falls from 51% on the UAT build to 35% on the live build. The soulution has identical configuration manager settings.

As our minimum covergae is less than 50% our build subsequently fails with the following error:

"NCover.Reporting.exe" exited with code 3.

A bit lost as to why the coverage drops when it is the same source from svn and identical test run being performed.

Has anyone else experienced this?

Answer 1

My recommendation would be to drop us an email at [email protected], ideally with the two coverage files attached. It's not unusual for us to see small coverage differences between Debug and Release builds running against the same tests (because the build types generate slightly different code), but never on the same build type running against the same test.