trace(...) doesn't log the value string

While running blacklist.c (hooks-v2) I noticed that the trace() function
shows the message but not the value.

for example at line 43
trace(SBUF("Memo: "), memo_ptr, memo_len, 1);
it logs only "Memo :"

I tried several cases in others places but had the same result.

As a workaround, I suppose, it could work by concat message+value