g++ -g does not emit DW_AT_explicit for explicit constructors. It should; I think it is impossible to correctly parse some expressions without this information.
-- Summary: g++ does not emit DW_AT_explicit Product: gcc Version: 4.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: tromey at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37959