How the gdb function throw_error works?

Hi there,

Function value_of_dwarf_block_entry in file dwarf2loc.c has a call to
function throw_error which seems will print out some error messages to
gdb user. I am pretty sure that the throw_error will be called in the
gdb built by myself. But I didn't see any error messages coming out
when using this gdb. What should I do to enable this throw_error
function? Please advise. Thanks.

BR,
Terry