Using Macports' gcc8 to build C programs and libraries

Andrew Udvare audvare at
Mon Apr 1 09:18:59 UTC 2019

> On 2019-04-01, at 05:10, Sean Lake <odysseus9672 at> wrote:
> In file included from MWReddening.c:1:
> /opt/local/lib/gcc8/gcc/x86_64-apple-darwin18/8.3.0/include-fixed/math.h:45:10:fatal
> error: sys/cdefs.h: No such file or directory
> #include <sys/cdefs.h>
>          ^~~~~~~~~~~~~

You should have this file at:


Assuming GCC 8 can use Apple's headers, add:


> Looking for similar errors on the web, I get pages like this
> that recommend installing a libc package. Will a similar solution work
> in Macports? If so, which package(s)? If not, will modifying my CFLAGS
> and LDFLAGS suffice? Currently, I have included "-I/opt/local/include"
> in CFLAGS and "-L/opt/local/lib" in LDFLAGS, but that's obviously not
> enough (or wrong).

There are some (dated) libc* packages. Run `port search 'Library for cross-platform C'`.
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