Variables and Environment

Shadowtree exposes reusable values through placeholders. Static values come from vars; dynamic values come from var_commands.

[vars]
ldflags = "-buildvcs=false"

[var_commands]
git_sha = "git rev-parse --short HEAD"

[recipes.build]
cmd = 'go build -ldflags="{ldflags}" -o "bin/app-{git_sha}" ./cmd/app'

Static Vars

Top-level vars are available to every recipe. Recipe-level vars override top-level values for that recipe.

[vars]
mode = "dev"

[recipes.release.vars]
mode = "release"

Static vars may reference other static or dynamic vars with the same {name} placeholder syntax.

Dynamic Vars

var_commands run when recipes are resolved for execution, printing, or help. They run from the source checkout. Surrounding whitespace is trimmed from stdout and the result becomes a placeholder value.

[var_commands]
version = "git describe --tags --always"

Dynamic vars are useful for values such as versions, commit IDs, detected paths, or generated labels that should be visible in --print --expanded.

Environment

Top-level env applies to recipe commands and top-level var_commands. Recipe-level env overrides top-level values for that recipe.

[env]
GOFLAGS = "-mod=readonly"

[recipes.test.env]
CGO_ENABLED = "0"

Environment values use raw placeholder expansion. Only {name} and {name:raw} are valid there; shell-specific modes such as {name:shell} are for shell command strings.

Reserved Names

run_id is built in and cannot be declared in vars, var_commands, recipe vars, or recipe arguments.