Changing '%qE %S' to '%<E %S%>' is missing a % and ICES constraints/req4.
Fixed thusly. -- Nathan Sidwell
2017-05-04 Nathan Sidwell <nat...@acm.org> * constraint.cc (diagnose_check_constraint): Fix %E thinko. Index: constraint.cc =================================================================== --- constraint.cc (revision 247613) +++ constraint.cc (working copy) @@ -2859,7 +2859,7 @@ diagnose_check_constraint (location_t lo { if (elide_constraint_failure_p ()) return; - inform (loc, "in the expansion of concept %<E %S%>", check, sub); + inform (loc, "in the expansion of concept %<%E %S%>", check, sub); cur = get_concept_definition (decl); tsubst_expr (cur, targs, tf_warning_or_error, NULL_TREE, false); return;