I prepared a package for mdadm containing a patch to fix bug #784070
(https://bugs.debian.org/784070) which prevents booting a software RAID
1 in degraded mode. The diff is attached to this message.
The previous package maintainer (Michael Tokarev) confirmed the source
of the
problem (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=784070#49)
and
several users confirmed that the patch fixes the bug. Moreover, the new
package maintainer (Dimitri John Ledkov, CC of this mail) agreed with
this
solution and gave me his consent to proceed with the upload
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=784070#230).