The problem was that when adding the webDAV-wagon to your build as an extension, you also get the commons-httpclient dependency to the maven runtime classpath. This wouldn’t be too bad, but the 1.0-beta2 version of the webDAV-wagon depends on commons-httpclient version 2.0.2. That’s way too old for canoo webtest and is also deprecated for almost a year now.

I found out that starting with maven 2.0.9 you don’t need to have an explicit reference to the webDAV-wagon as extension anymore.

E voilà! Suddenly it worked. Maven 2.0.9 also seems to work with version 3.1 of commons-httpclient, the same version canoo webtest depends on.

So, if you get a ‘NoSuchMethodFound’ for HttpConnectionManager.getParams() first check if you’re using the webDAV-wagon extension first.