openexr/OpenEXR_Viewers/config/LocateCg.cmake issue on Linux

[etheory]

Hi there!

I've been struggling to build OpenEXR on CentOS-7.4.5 with CMake-3.14.5 due to the following:

add_library(Cg UNKNOWN IMPORTED GLOBAL)
and
add_library(CgGL UNKNOWN IMPORTED GLOBAL)

only get correctly added if I change them to:

add_library(Cg SHARED IMPORTED GLOBAL)
and
add_library(CgGL SHARED IMPORTED GLOBAL)

otherwise I get the error:

NOTICE-- Found Cg library
CMake Error at OpenEXR_Viewers/config/LocateCg.cmake:27 (add_library):
add_library cannot create ALIAS target "Cg::Cg" because target "Cg" is not
a library.
Call Stack (most recent call first):
OpenEXR_Viewers/CMakeLists.txt:47 (include)

For both Cg and CgGL

Which appears to be thrown by:
add_library(Cg::Cg ALIAS Cg)
and
add_library(Cg::CgGL ALIAS CgGL)

When their target type is

UNKNOWN

Are you aware of this issue and is there anything I can do about it aside from hacking the CMake?

Thanks,
Luke

[fnaum]

I think that was fixed in cmake-3.15.0
https://gitlab.kitware.com/cmake/cmake/issues/18327
https://gitlab.kitware.com/cmake/cmake/merge_requests/3148
I did not try that version, but updating to 3.16.4 did the trick.

So I guess you'll need cmake_minimum_required(VERSION 3.15) here

[etheory]

Thanks @fnaum!