can you spot the problem in reap() function in /sys/src/libc/9sys/dial.c? hint: in notedeath() there is a tokenize(exitsts, ...)
static int reap(Dest *dp) { char exitsts[2*ERRMAX]; if (outstandingprocs(dp) && await(exitsts, sizeof exitsts) >= 0) { notedeath(dp, exitsts); return 0; } return -1; }