YAMAMOTO Mitsuharu schrieb am Mo., 25. Sep. 2017 um 02:29 Uhr: > >>>>> 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.