These remnants weren't catched up before, because previously cmake
was just issuing a warning for missing includes:
/usr/ports/pobj/ctl-1.5.2/CTL-ctl-1.5.2/lib/IlmCtl/CtlTypeStorage.cpp:67:20: warning: alloca.h: No such file or directory
While now (cmake>=3.6) it properly errors out.
The Color Transformation Language, or "CTL," is a portable and
platform-independent scripting language and interpreter, is intended to
be used as a building block for color management systems as well as for
sharing transforms in a common format.
from John Danks, with some tweaks by me
