I have the following two disk raid0 md device:

# cat /etc/mdadm.conf
DEVICE /dev/sdc1 /dev/sdd1
ARRAY /dev/md0 level=raid0 UUID=e8a209ab:4e9060be:702493b4:04034197

I converted over to mdadm yesterday from raidtools when I upgraded to 10.1 beta2,
and raidtools was dropped.  It wasn't starting up the device on bootup, and
after poking around I noticed mdadm --assemble was core dumping.

root@fairseas mdadm-2.2 # ./mdadm --assemble --scan
Segmentation fault (core dumped)
root@fairseas mdadm-2.2 # file core
core: ELF 32-bit LSB core file Intel 80386, version 1 (SYSV), SVR4-style
root@fairseas mdadm-2.2 # gdb mdadm core
GNU gdb 6.4
Copyright 2005 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
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This GDB was configured as "i586-suse-linux"...Using host libthread_db library "/lib/libthread_db.so.1".

Core was generated by `./mdadm --assemble --scan'.
Program terminated with signal 11, Segmentation fault.

warning: Can't read pathname for load map: Input/output error.
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
#0  0x08051d56 in Assemble (st=0x0, mddev=0x806a1c8 "/dev/md0", mdfd=3, ident=0x806a1f0,
    conffile=0x0, devlist=0x806a018, readonly=0, runstop=0, update=0x0, verbose=0, force=0)
    at Assemble.c:222
222                     if (ident->uuid_set && (!update && strcmp(update, "uuid")!= 0) &&
(gdb) where
#0  0x08051d56 in Assemble (st=0x0, mddev=0x806a1c8 "/dev/md0", mdfd=3, ident=0x806a1f0,
    conffile=0x0, devlist=0x806a018, readonly=0, runstop=0, update=0x0, verbose=0, force=0)
    at Assemble.c:222
#1  0x0804c74c in main (argc=3, argv=0xbfe49154) at mdadm.c:966
(gdb) list
217                     } else {
218                             tst->ss->getinfo_super(&info, &ident2, super);
219                     }
220                     if (dfd >= 0) close(dfd);
221
222                     if (ident->uuid_set && (!update && strcmp(update, "uuid")!= 0) &&
223                         (!super || same_uuid(info.uuid, ident->uuid, tst->ss->swapuuid)==0)) {224                             if ((inargv && verbose >= 0) || verbose > 0)
225                                     fprintf(stderr, Name ": %s has wrong uuid.\n",
226                                             devname);
(gdb) whatis ident
type = mddev_ident_t
(gdb) p ident.uuid_set
$5 = 1
(gdb) p update
$6 = 0x0

Looks like the test should be (update && strcmp(update, "uuid")!= 0) instead.
Attached patch fixes it for me.