Recently, libopenraw-0.1.0 was released. It provides libopenraw-gnome pkgconfig version 0.1.0 Sadly, older versions of libopenraw (0.0.x) provided libopenraw-gnome version 1.0.0 So, tumbler needs to adjust it's build time config to detect and use the new libopenraw. (And probibly still work with the old version too).
Created attachment 7009 0001-Fix-finding-libopenraw-0.1.0-due-to-changed-pkg-conf.patch This patch adds support for the new pkg-config name. Upstream doesn't seem to have done any API changes, and I can confirm that tumbler builds fine against both 0.1.0 and 0.0.9 versions for me with it.
Thx for tha patch, it has been applied to git master and will be included in the next releases.