user mode linux aborts right away

./linux rootfstype=hostfs mem=64M rw init=/bin/bash Core dump limits : soft - NONE hard - NONE Checking that ptrace can change system call numbers...OK Checking syscall emulation patch for ptrace...OK Checking advanced syscall emulation patch for ptrace...OK Checking environment variables for a tempdir...none found Checking if /dev/shm is on tmpfs...OK Checking PROT_EXEC mmap in /dev/shm...OK Adding 10289152 bytes to physical memory to account for exec-shield gap Aborted (core dumped) I'm using linux-4.4.35 which I compiled using gcc --version gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609 It's possible I should be using a package, but it's not available in ubuntu 16.04 I'm following the instructions from here, verbatim. I used a newer linux kernel, since 3.10 doesn't compile with GCC-5 https://techoverflow.net/blog/2013/07/09/user-mode-linux-for-beginners-part-1-setup-and-first-vm/