supermin dies while running virt-sysprep. "clonevm" is a shell script I wrote.
It creates a VM and runs virt-sysprep to do some final customizations on it.

virt-sysprep: error: libguestfs error: /usr/bin/supermin killed by signal 
11 (Segmentation fault).
To see full error messages you may need to enable debugging.
Do:
  export LIBGUESTFS_DEBUG=1 LIBGUESTFS_TRACE=1
and run the command again.  For further information, read:
  http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs
You can also run 'libguestfs-test-tool' and post the *complete* output
into a bug report or message to the libguestfs mailing list.

If reporting bugs, run virt-sysprep with debugging enabled and include the 
complete output:

  virt-sysprep -v -x [...]

clonevm: ERROR in virt-sysprep --operations
defaults,-udev-persistent-net,-ssh-userdir --quiet --hostname "$newname" -a
"$NEWROOT" --script "$TMPD/rename_ifaces" at clonevm:223

apollon:/mnt/vms # coredumpctl gdb /usr/bin/supermin
           PID: 31186 (supermin)
           UID: 0 (root)
           GID: 0 (root)
        Signal: 11 (SEGV)
     Timestamp: Thu 2017-06-29 14:52:50 CEST (17min ago)
  Command Line: /usr/bin/supermin --build --if-newer --lock
/var/tmp/.guestfs-0/lock --copy-kernel -f ext2 --host-cpu x86_64
/usr/lib64/guestfs/supermin.d -o /var/tmp/.guestfs-0/appliance.d
    Executable: /usr/bin/supermin
 Control Group:
/user.slice/user-17326.slice/user@17326.service/gnome-terminal-server.service
          Unit: user@17326.service
     User Unit: gnome-terminal-server.service
         Slice: user-17326.slice
     Owner UID: 17326 (mwilck)
       Boot ID: 43ccdab44d4340198c8783756adab716
    Machine ID: a0385656b74c9241b77c1bb6577a603b
      Hostname: apollon.suse.de
       Storage:
/var/lib/systemd/coredump/core.supermin.0.43ccdab44d4340198c8783756adab716.31186.1498740770000000.lz4
       Message: Process 31186 (supermin) of user 0 dumped core.

Core was generated by `/usr/bin/supermin --build --if-newer --lock
/var/tmp/.guestfs-0/lock --copy-ker'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  strlen () at ../sysdeps/x86_64/strlen.S:106
106        movdqu    (%rax), %xmm4
(gdb) bt
#0  strlen () at ../sysdeps/x86_64/strlen.S:106
#1  0x00007ff9aee064c8 in indexGet (dbi=dbi@entry=0x559622e29b60,
keyp=keyp@entry=0x1 <error: Cannot access memory at address 0x1>, 
    keylen=keylen@entry=0, set=set@entry=0x7ffe28126258) at rpmdb.c:232
#2  0x00007ff9aee09354 in indexIterInit (keylen=0, keyp=0x1, rpmtag=1000,
db=0x559622d9cc20) at rpmdb.c:1808
#3  rpmdbInitIterator (db=0x559622d9cc20, rpmtag=rpmtag@entry=1000,
keyp=keyp@entry=0x1, keylen=keylen@entry=0) at rpmdb.c:1841
#4  0x00007ff9aee33149 in rpmtsInitIterator (ts=0x559622baafb0,
rpmtag=rpmtag@entry=1000, keyp=0x1, keylen=keylen@entry=0)
    at rpmts.c:248
#5  0x0000559621c4df39 in supermin_rpm_installed (rpmv=<optimized out>,
pkgv=<optimized out>) at librpm-c.c:200
#6  0x0000559621c05ab7 in camlRpm__query_2995 ()
#7  0x0000559621c06b6f in camlRpm__rpm_package_of_string_2993 ()
#8  0x0000559621c05905 in camlRpm__fun_3482 ()
#9  0x0000559621c20833 in camlArray__fold_left_2295 () at array.ml:149
#10 0x0000559621c05a56 in camlRpm__fun_3479 ()
#11 0x0000559621c20833 in camlArray__fold_left_2295 () at array.ml:149
#12 0x0000559621c06e93 in camlRpm__rpm_get_all_requires_3016 ()
#13 0x0000559621c0031c in camlBuild__build_1568 ()
#14 0x0000559621bfe3c2 in camlSupermin__main_1542 ()
#15 0x0000559621bfe8c0 in camlSupermin__entry ()
#16 0x0000559621bfa5d9 in caml_program ()
#17 0x0000559621c6af94 in caml_start_program ()
#18 0x0000559621c6b365 in caml_main (argv=0x7ffe281267e8) at startup.c:138
#19 0x0000559621bfa18c in main (argc=<optimized out>, argv=<optimized out>) at
main.c:35

The "keyp=0x1" in frame #4 seems to be the problem. This looks like an ocaml/C
interface problem.