assertion failed when renaming the root filesystem
Trying to "zfs rename" the root filesystem should fail, according to the rootpool_003_neg test. However, it fails by triggering an assertion in libzfs, not by returning any sensible error code. On FreeBSD, renaming the root filesystem works just fine, so I'm not sure why it should be disallowed by the test suite. In any case, asserting is always bad behavior:
$ sudo zfs rename rpool/ROOT rpool/newfs
assertion failed for thread 0xfede2a40, thread-id 1: !clp->cl_alldependents, file ../common/libzfs_changelist.c, line 499
This is on OmniOS using the OpenZFS kernel built from 0ef125dcb26572fff77004ee336090e8e3e5ac12, at March-20-2017.