Run shellcheck on direnvrc during checkPhase

default.nix

@@ -11,6 +11,7 @@
 , re
 , reason
 , sha
+, shellcheck
 , upx
 ,
 }:
@@ -38,6 +39,9 @@ buildDunePackage {
   # patchELF can't handle UPX'd binaries
   # We produce a static OCaml binary that
   dontPatchELF = true;
+  postCheck = ''
+    ${shellcheck}/bin/shellcheck direnvrc
+  '';
   postPatch = ''
     substituteInPlace direnvrc --replace-fail "@flake_env@" "$out/bin/flake_env"
   '';

direnvrc

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 # The below code is taken largely from nix-direnv.
 # nix-direnv's license is replicated below:
 # 
@@ -38,7 +40,8 @@ use_flake_env() {
   local old_tempdir=${TEMPDIR:-__UNSET__}
   local old_xdg_data_dirs=${XDG_DATA_DIRS:-}
 
-  local ld=$(direnv_layout_dir)
+  local ld
+  ld=$(direnv_layout_dir)
   export direnv
 
   local flake_reference="${1:-"."}"