Gentoo's Bugzilla –
Attachment 580272 Details for
Bug 688410=media-gfx/mandelbulber-2.12-r1 missing dependency -> USE=opencl - In file included from src/algebra.hpp:51, from src/algebra.cpp:40: src/include_header_wrapper.hpp:62:10: fatal error: CL/cl.hpp: No such file or directory