I just unboxed my new MacBook Pro, running Yosemite 10.10.5. When I went through the setup procedure, it didn't ask me what password to use for my account, and just set it to that of my AppleID. (I only discovered that by trial and error.)
I now want to set my password to the same one that I use on the old Mac; but the password (eight characters, includes some digits, which BTW is also exactly true of my AppleID password) is rejected.
When I simply run passwd while logged in as myself, it fails saying:
passwd: general failure
And when I run it as sudo passwd mike, it is more precise:
passwd: Password change failed because password is too short. Password change failed because password is too short.
(Yes, it says it twice.)
It also does this when I use 13-character password. It doesn't say how long a password it requires and I am not minded to determine this by trial and error.
How can I force my Mac to accept the password of my choice?