diff --git a/release.nix b/release.nix
index ee5ee7cb2d04a082d29da003fcf1c451fc28ab12..11c1d5e3a6c4e75e92d40b77870923341251b983 100644
--- a/release.nix
+++ b/release.nix
@@ -1,3 +1,7 @@
+# usage:
+#   nix-build release.nix -A espressif-esp32-tools
+#   nix-build release.nix -A espressif-esp32-tools --arg crossAarch64 true
+#   mkdir tmp; cd tmp; nix-shell ../release.nix -A espressif-esp32-tools --arg crossAarch64 true
 let
   nixpkgs = import <nixpkgs>;
   overlay = import ./overlay.nix;