Coverage tests: lots of libgcov profiling errors

[jagalactic]

In at least some cases this appears to be due to some but not all tests running as root - such that the non-root tests can't write some file that they need to write.

[jagalactic]

A sample:

libgcov profiling error:/home/jmg/w/famfs/coverage/testlib/CMakeFiles/famfstest.dir/xrand.c.gcda:Error writing
+ sudo /home/jmg/w/famfs/coverage/famfs clone /mnt/famfs/original /mnt/famfs/clone
libgcov profiling error:/home/jmg/w/famfs/coverage/testlib/CMakeFiles/famfstest.dir/xrand.c.gcda:Error writing
+ sudo /home/jmg/w/famfs/coverage/famfs clone -v /mnt/famfs/original /mnt/famfs/clone1
libgcov profiling error:/home/jmg/w/famfs/coverage/testlib/CMakeFiles/famfstest.dir/xrand.c.gcda:Error writing
+ sudo /home/jmg/w/famfs/coverage/famfs clone -v /mnt/famfs/clone /mnt/famfs/clone2
libgcov profiling error:/home/jmg/w/famfs/coverage/testlib/CMakeFiles/famfstest.dir/xrand.c.gcda:Error writing

The tests above are running as root, so non-rootness may cause some problems, but not all. Or perhaps my theory is wrong.