On 22-08-23 18:06 , Eli Zaretskii wrote:
>> From: Lars Ingebrigtsen <larsi@gnus.org>
>> Cc: eliz@gnu.org,  emacs-devel@gnu.org,  luangruo@yahoo.com
>> Date: Tue, 23 Aug 2022 16:43:40 +0200
>>
>> The most recalcitrant thing is ./configure, of course -- it's
>> single-threaded.
> Are you using -C ?  It makes the configure script fly.  Most of the
> changes in the script nowadays don't need a full reconfiguration, and
> seldom even add new variables.
>
Interesting.   How are you using --config-cache?

I tried here two './configure --config-cache --with-native-compilation' 
in a row (no config.cache initially), and the second run failed because 
of something I don't understand.  Basically, it first says libgccjit.h 
found, and then fails because it can't find libgccjit.h.

Is this a bug, or am I doing it wrong?