A cycle of git bisect building leads me here:

255573996cc997cb61be9adad3e8fcaa78db5d1f is the first bad commit
commit 255573996cc997cb61be9adad3e8fcaa78db5d1f
Author: Marek Olšák <marek.olsak@amd.com>
Date:   Mon Oct 9 18:56:22 2017 +0200

    st/dri: implement __DRIimageExtension::validateUsage properly

    Reviewed-by: Daniel Stone <daniels@collabora.com>
    Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

:040000 040000 691ace5458e444a262bd2632b0234f7c08711674
181aa1f345cafc40db98187dd9e66b115c8f7e52 M      src

I'm not familiar enough with C or this codebase to render an opinion about why
this commit would have broken things, but I'd love to assist if someone with
more perspective needs me to run/test things to determine a resolution here.