#1902 fix some of broken nightly builds

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17789 b5f69653-2bf5-0310-8201-b0dafb8e1405
Fix coverage for #1992.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17790 b5f69653-2bf5-0310-8201-b0dafb8e1405
#1902 revert r17773 and r17789

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17793 b5f69653-2bf5-0310-8201-b0dafb8e1405