[Gc] OS X 10.10 install

[Hans Aberg]

I get, on OS X 10.10.1, a ./configure error [1] with gc-7.4.2: it can’t find libatomic_ops-7.4.2, which I have installed on the system, nor does linking help.


1. ./configure
...
checking for dladdr... yes
checking sys/dg_sys_info.h usability... no
checking sys/dg_sys_info.h presence... no
checking for sys/dg_sys_info.h... no
checking for pkg-config... no
checking for ATOMIC_OPS... no
configure: error: libatomic_ops is required. You can either install it on
your system, or fetch and unpack a recent version into the
source directory and link or rename it to libatomic_ops.

[Hans Aberg]

This issue is resolved: one must have pkg-config installed; it is not there by default on OS X. Also, pkg-config must be in /usr/local, it seems: I had another in /opt/ from MacPorts, where possibly gc does not look.