How to speed up rom compilation

What is ccache?

You can optionally tell the build to use the ccache compilation tool. Ccache acts as a compiler cache that can be used to speed up rebuilds. This works very well if you use make clean often, or if you frequently switch between different build products.

1. Open .bashrc to set cache export

gedit .bashrc
--- At last of bashrc file---
# ccache
export USE_CCACHE=1

2. Go to your rom folder & paste the following

cd android/roms/los-n (example rom folder)
prebuilts/misc/linux-x86/ccache/ccache -M 50G (for linux)
prebuilt/linux-x86/ccache/ccache -M 50G (for Mac OS)

3. Now enable it

source ~/.bashrc