Subject: bug#48117: 28.0.50; Update of loaddefs.el during normal build is unreliable

From: Gregory Heytings <[email-masked]>
Date: Sat, 01 May 2021 12:29:12 +0000

>>> Your proposal would produce marginally better results for a 
>>> significantly longer build time, so I don't think it's a net win.
>>
>> If ldefs-boot.el is updated, say, once a week, this would force the 
>> regeneration of the loaddefs files at most once a week.  Wouldn't that 
>> be a reasonable compromise?
>
> Compromise between which alternatives?
>

I see at least the following possible alternatives:

- the current situation, which you describe in your original post, in 
which the loaddefs files need to be regenerated manually (inconvenient)

- regenerating the loaddefs files for each make invocation (inefficient)

- copying the ldefs-boot.el onto loaddefs.el when it is more recent (which 
IIUC could lose local additions to loaddefs.el)

- automatically regenerating the loaddefs files when ldefs-boot.el is more 
recent than loaddefs.el (which I understand could be a bit slow)

- issue only a warning when make is invoked and ldefs-boot.el is more 
recent than loaddefs.el (and perhaps add a autoloads or loaddefs target to 
the main Makefile)