>>>>> On Sun, 24 Sep 2017 07:49:55 +0000, Philipp Stephani <p.stephani2@gmail.com> said:
>> I take it you upgraded Xcode the other day? (To version 9, I
>> think?)
>>
> Yes, indeed.
Probably You need to execute "$ xcode-select --install" to install
Command Line Tools for Xcode. You can actually go without it by
tweaking some environment variables and/or compiler arguments, but I
wouldn't recommend that unless you have a shortage of disk space and
you really understand what you are doing.
OK, the warning is indeed gone after that, thanks.
Should we put something in
configure.ac that checks for this? It's a bit subtle because compilation almost completely works without it.