write_fhb error message improvement

gistfile1.txt

diff --git a/src/io/io.c b/src/io/io.c
index 5762f0666..be92c0af6 100644
--- a/src/io/io.c
+++ b/src/io/io.c
@@ -141,7 +141,7 @@ void MVM_io_write_bytes(MVMThreadContext *tc, MVMObject *oshandle, MVMObject *bu
         MVM_exception_throw_adhoc(tc, "write_fhb requires a native array to read from");
     if (((MVMArrayREPRData *)STABLE(buffer)->REPR_data)->slot_type != MVM_ARRAY_U8
         && ((MVMArrayREPRData *)STABLE(buffer)->REPR_data)->slot_type != MVM_ARRAY_I8)
-        MVM_exception_throw_adhoc(tc, "write_fhb requires a native array of uint8 or int8");
+        MVM_exception_throw_adhoc(tc, "write_fhb requires a native array of uint8 or int8, but got %s", MVM_6model_get_debug_name(tc, buffer));

     output = (char *)(((MVMArray *)buffer)->body.slots.i8 + ((MVMArray *)buffer)->body.start);
     output_size = ((MVMArray *)buffer)->body.elems;