Action (b0.B0_unit.Action)

val exec_cwd : (build -> t -> B0_std.Fpath.t B0_std.Fut.t) B0_meta.key

val scope_cwd : build -> t -> B0_std.Fpath.t B0_std.Fut.t

val exec_env : 
  (build -> t -> B0_std.Os.Env.assignments B0_std.Fut.t) B0_meta.key

val exec : action

val exec_file : 
  build ->
  t ->
  B0_std.Fpath.t ->
  B0_std.Cmd.t ->
  B0_std.Os.Exit.t B0_std.Fut.t