By default, Postgis will try to compile with gettext support. This creates a problem on macs (at least on mavericks). Whilst OS X provides the gettext library, it is incomplete and missing certain dylibs. As a result, Postgis' .configure will try to compile with gettext support and fail.

There are two ways around this:

1. Remove gettext support for a default install (possibly also providing a flag --with-gettext for those who need it). This requires a change to the recipe (or can we add compilation flags to pex install ?).
2. Install gettext via homebrew followed by brew link --force gettext. One should unlink gettext after building postgis as this will conflict with the standard OS X library (as per homebrew's caveats).

Option 1 is probably better. From Postgis' installation reference:

--with-gettext=no
By default PostGIS will try to detect gettext support and compile with it, however if you run into
incompatibility issues that cause breakage of loader, you can disable it entirely with this command. Refer to ticket http://trac.osgeo.org/postgis/ticket/748 for an example issue solved by configuring with this. NOTE: that you aren't missing much by turning this off. This is used for international help/label support for the GUI loader which is not yet documented and still experimental.

I'm not sure how to implement such a change to pex's postgis recipe, so I can't provide a PR. Either way, leaving this issue here in case people run into trouble.

joao.