void mdb_warn(const char *format, ...);
Print an error or warning message to standard error. The mdb_warn() function accepts a format string and variable argument list that can contain any of the specifiers documented for mdb_printf(). However, the output of mdb_warn() is sent to standard error, which is not buffered and is not sent through the output pager or processed as part of a dcmd pipeline. All error messages are automatically prefixed with the string "mdb:".
In addition, if the format parameter does not contain a newline (\n) character, the format string is implicitly suffixed with the string ": %s\n", where %s is replaced by the error message string corresponding to the last error recorded by a module API function. For example, the following source code:
if (mdb_lookup_by_name("no_such_symbol", &sym) == -1) mdb_warn("lookup_by_name failed");
produces this output:
mdb: lookup_by_name failed: unknown symbol name