Looks like loc2c-test indicates that the *prev* and *next* variables are
available.
It says they are in scope, i.e. it knows what variables you're talking
about. That doesn't mean their values are available at that PC location.
If that is the distinction that matters, then certainly stap should give a
more clear error message about it.
Did you try "loc2c-test -k 0x... prev pid"? You should always use that
(loc2c-test with identifier args) to debug $identifier resolution problems.
That step should thoroughly disambiguate loc2c bugs vs translator proper
bugs.
Thanks,
Roland