package mailutils tags 517457 + patch done readmsg.c parses its command line in to option-value pairs, which it then parses a second time. Options without arguments need a fake argument added in the first parse, otherwise the second parse segfaults. Patch attached.
It also appears to embed bits of libc's getopt (in the lib/getopt* files) instead of using the system library. Steve
--- a/readmsg/readmsg.c +++ b/readmsg/readmsg.c @@ -104,11 +104,11 @@ readmsg_parse_opt (int key, char *arg, struct argp_state *astate) break; case 'p': - mu_argp_node_list_new (&lst, "form-feeds", arg); + mu_argp_node_list_new (&lst, "form-feeds", "yes"); break; case 'a': - mu_argp_node_list_new (&lst, "show-all-match", arg); + mu_argp_node_list_new (&lst, "show-all-match", "yes"); break; case ARGP_KEY_INIT: