B0_srcstype sel = [ | `Dir of B0_std.Fpath.t| `Dir_rec of B0_std.Fpath.t| `File of B0_std.Fpath.t| `Fut of B0_build.t -> B0_std.Fpath.Set.t B0_std.Fut.t| `X of B0_std.Fpath.t ]type sels = sel listval select : B0_build.t -> sels -> t B0_std.Fut.tval by_ext : t -> B00_fexts.map