CMake: No ANSI colored output when using CMake + Ninja

[maxrdz]

Description

Linux users are recommended to run cmake -G Ninja .. when generating the build files for Panda through CMake. When using Ninja, no color output is shown on the terminal making it hard to read / debug compiler messages. Ninja buffers output, so tools are writing to a pipe, not directly to the terminal, so auto-detection may turn color diagnostics off conservatively.

Steps to Reproduce

Use Ninja as your CMake generator.

Environment

• Operating system: Arch Linux
• System architecture: x86_64
• Panda3D version: 1.10.14
• Installation method: source
• Python version (if using Python): N/A
• Compiler (if using C++): GCC