diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/README.md b/README.md
index 82758c3..f5a059e 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ Types and bindings to connect easily to a running Holochain conductor from Rust.
 
 ``` bash
 ./build-fixture.sh
-cargo test
+cargo test --release
 ```
 
 ## Contribute
diff --git a/build-fixture.sh b/build-fixture.sh
index 546581a..a48d4cb 100755
--- a/build-fixture.sh
+++ b/build-fixture.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 CARGO_HOME=./fixture/zomes/foo/.cargo cargo build -p test_wasm_foo --release --target wasm32-unknown-unknown --target-dir ./fixture/zomes/foo/target
diff --git a/flake.nix b/flake.nix
index f2c2e01..8fa533d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -17,9 +17,11 @@
               inputs'.holonix.packages.lair-keystore
               inputs'.holonix.packages.rust
               pkgs.go
+              pkgs.perl
             ] ++ (pkgs.lib.optionals pkgs.stdenv.isDarwin [
               # needed to build Holochain on macos
               pkgs.darwin.apple_sdk.frameworks.SystemConfiguration
+              pkgs.bzip2
             ]);
           };
         };