>>> And it depends on the error.  Put the following into simple.el, and 
>>> you'll get a warning from the byte compiler, but you won't get any 
>>> errors when building:
>>
>> This is because of dcf9cd47ae.  Patch attached, which will hopefully 
>> fix the other silent failures you experience.
>
> Thanks, but why condition that on batch mode?  Does the problem happen 
> in any batch-mode invocation, and if so, why?
>

When Emacs has been built, the problem does not seem to exist anymore. 
FWIW, I'm not sure it makes sense to call substitute-command-keys there, 
even in non-batch mode, but it should probably be okay to limit the scope 
of the fix to something narrower.  Updated patch attached, this time 
against the current trunk.