With the current inode-uprobes, we don't have any mechanism to do .return probes. Many of our uprobes testsuite assume that .return always comes along for the ride, so we currently get many failures just due to missing .return. As much as possible, we should split up uprobes tests that may work partly with and without .return probes, and then mark tests UNSUPPORTED where appropriate.
This is also affecting at least at_var.exp and global_var.exp which test various combinations of @var() with things like @entry() and so rely on being able to set return probes and check the results.
commit 9c41fd et al.