Daemon (buckd)

The first time that a Buck2 command is run, Buck2 starts a daemon process for the current project. For subsequent commands, Buck2 checks for the running daemon process and, if found, uses the daemon to execute the command. Using the Buck2 daemon can save significant time as it enables Buck to share cache between Buck2 invocations.

By default, there is 1 daemon per project root, you can run multiple daemons in the same project by specifying an isolation dir.

While it runs, the Buck daemon process monitors the project's file system for changes. The Buck daemon excludes from monitoring any subtrees of the project file system that are specified in the [project].ignore setting of .buckconfig.

You can see detailed information about the status of the daemon by running buck2 status.

Killing or disabling the Buck daemon

The Buck daemon process is killed if buck2 clean or buck2 kill commands are run. Note that they won't kill the daemon associated with custom isolation dirs. To do that, run using the --isolation-dir option (buck2 --isolation-dir <dir> <command>)