Buck2 configuration

.buckconfig is generated from toolkit/templates/buckconfig and project.json by br2-sync. Do not edit it; put project settings in project.json and per-run settings on the command line (br2 build --mode ..., or --config br2.<key>=<value> to Buck2).

[br2]

Key	Default	Meaning
remote_cache	false	look results up in the Buildbarn cache
cache_uploads	false	upload results to it (leave off for untrusted builds)
remote_execution	false	run actions on the Buildbarn worker
local_execution	true	allow actions to run locally (set false with remote_execution)
native	empty	comma-separated packages built by Buck2 actions instead of make <pkg>
native_project	from native/	the subset of native that lives in this project's native/ directory
external	from project.json	does the project have a BR2_EXTERNAL tree
rootfs_image	from project.json	the image the rootfs action copies out
fragment	from project.json	the config fragment applied after the defconfig
dev_tools	false	dev mode: the toolkit's scripts are referenced by path, not declared as inputs
cache_salt	empty	added to every action's environment; a different value is a fresh cache generation

[buck2_re_client]

Key	Value
engine_address, action_cache_address, cas_address	grpc://localhost:8980 (the scheme is required)
tls	false
instance_name	the project name, plus a suffix per mode (br2 build sets it)

Cells and the prelude

The project is a single cell (root = .) plus the prelude bundled with the pinned buck2 binary ([external_cells] prelude = bundled). The execution platform is root//platforms:default, which reads the [br2] switches; the prelude's own default hard-codes no remote.

Watched paths

[project] ignore keeps Buck2's file watcher off .git, buildroot-src/.git, buildroot-src/output, buildroot-src/dl, out and tools. Buildroot's output is elsewhere on purpose; see Debugging.