Hi,

I got a similar issue on core-updates-frozen with opencv.

I solved it in 463a47f4d737ad645639ed32a1c97cfc3bf00ff0 with:

--8<---------------cut here---------------start------------->8---
-    (search-input-directory inputs "include/OpenEXR")
+    (string-drop-right
+     (search-input-file inputs "include/OpenEXR/ImathVec.h")
+     11)
--8<---------------cut here---------------end--------------->8---

It guess this will also work for bender, but I can't test right now
because openvdb which bender depends on fails to build.

I suspect it happens because there are several inputs with
a "include/OpenEXR" directory and 'search-input-directory' doesn't
return the one we're looking for.