Enable sstate cache

Sstate Cache Background [1]

To speed up the build process, sstate provides a cache mechanism, where sstate files from server can be reused to avoid build from scratch if the producer and consumer of the sstate have the same environment. In the best case, this can reduce build time by more than 80%.

Sstate Cache Server

The default sstate files directory is sstate-cache under build dir. An sstate mirror is available via sstate.karo-electronics.de.

It is enabled by default in conf/local.conf in your build directory:

SSTATE_MIRRORS = "file://.* http://sstate.karo-electronics.de/${DISTRO_CODENAME}/PATH;downloadfilename=PATH"

The special “PATH” suffix is important as it is automatically expanded to the correct value for native packages (which are split by the host distribution being used).

Verify Sstate is Working

If sstate works, you can see something like:

...
Checking sstate mirror object availability
...
SetScene Tasks

[1]

More information in official documentation, here.