--- a/Cargo.lock
+++ b/Cargo.lock
@@ -30,6 +30,17 @@
 checksum = "216261ddc8289130e551ddcd5ce8a064710c0d064a4d2895c67151c92b5443f6"
 
 [[package]]
+name = "async-trait"
+version = "0.1.59"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31e6e93155431f3931513b243d371981bb2770112b370c82745a1d19d2f99364"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "atty"
 version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -265,6 +276,7 @@
 dependencies = [
  "annotate-snippets",
  "anyhow",
+ "async-trait",
  "bincode",
  "hashbrown 0.13.1",
  "jrsonnet-gcmodule",