buck-out

Buck2 stores build artifacts in a directory named buck-out in the root of your project. You should not make assumptions about where Buck2 places your build artifacts within the directory structure beneath buck-out as these locations depend on Buck2's implementation and could potentially change over time. Instead, to obtain the location of the build artifact for a particular target, you can use one of the --show-*-output options with the buck2 build or buck2 targets commands, most commonly --show-output. For the full list of ways to show the output location, you can run buck2 build --help or buck2 targets --help.

buck2 targets --show-output <target>
buck2 build --show-output <target>