The function add_compile_options was added to CMake version 2.8.12 and later but your minimum is 2.8 which will not work

[nicebub]

Describe the bug
Will not build with CMAKE prior to version 2.8.12

Steps To Reproduce
Try to build with version CMAKE < 2.8.12

Version and Platform

• json-c version: [e.g. json-c-0.15, or a specific commit hash]
• OS: [e.g. Ubuntu 18.04.6, ]
• cmake version 2.8.4

[hawicz]

It's probably past time to bump the minimum version. Do you know of some system still stuck on cmake<2.8.12

[nicebub]

unfortunately.

[hawicz]

unfortunately past time? or unfortunately you know of some system that can't use a newer cmake? If the latter, why not?

[nicebub]

yes and yes. I only have control of specific tools and libraries.