embed git describe for version

src/Sand/SandDaemon.lean

@@ -1,6 +1,7 @@
 import «Sand».Basic
 import «Sand».Time
 import «Sand».Message
+import «Sand».Version
 import Batteries
 
 open System (FilePath)
@@ -204,7 +205,7 @@ def envFd : IO (Option UInt32) := OptionT.run do
 def systemdSockFd : UInt32 := 3
 
 def SandDaemon.main (_args : List String) : IO α := do
- IO.eprintln "Starting Sand daemon."
+ IO.eprintln s!"Starting Sand daemon {Sand.version}"
 
  let fd ← match ← envFd with
  | none => do

src/Sand/Version.lean

@@ -0,0 +1,19 @@
+import Lean
+
+open Lean.Elab.Term
+open Lean.Elab (throwUnsupportedSyntax)
+open Lean.Syntax (mkStrLit)
+open Lean (Expr)
+
+private def getVersion : IO String :=
+ String.trimRight <$> IO.Process.run { cmd := "git", args := #["describe"] }
+
+syntax (name := versionStr) "version_str" : term
+
+@[term_elab versionStr] 
+private def elabVersionStr : TermElab
+ | `(version_str), _ => do
+ return Expr.lit <| .strVal (← getVersion)
+ | _, _ => throwUnsupportedSyntax
+
+def Sand.version : String := version_str