Subject: bug#21968: Apparent regression on the undo command

From: Eli Zaretskii <[email-masked]>
Date: Mon, 14 Dec 2015 22:09:02 +0200

> From: John Wiegley <[email-masked]>
> Date: Mon, 14 Dec 2015 12:04:59 -0800
> Cc: David Reitter <[email-masked]>, [email-masked]
> 
> I just built emacs-25, but most actions that I take give me errors like the
> following:
> 
>     Symbol’s function definition is void: undo-auto-amalgamate
> 
> Have I omitted to do something?

I don't know, but that function is in simple.el.  Did you build in a
clean directory?