3 files changed, 43 insertions, 0 deletions

diff --git a/nix/default.nix b/nix/default.nix
index cef8800..f3e35e2 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -8,4 +8,5 @@ self: super:
   rolling-directory = self.callPackage ./rolling-directory.nix {};
   recv = self.callPackage ./recv.nix {};
   notmuch-tcp = self.callPackage ./notmuch-tcp.nix {};
+  persistent-nix-shell = self.callPackage ./persistent-nix-shell.nix {};
 }
diff --git a/nix/persistent-nix-shell.nix b/nix/persistent-nix-shell.nix
new file mode 100644
index 0000000..7b371c6
--- /dev/null
+++ b/nix/persistent-nix-shell.nix
@@ -0,0 +1,22 @@
+{ stdenv
+, zsh
+}:
+
+stdenv.mkDerivation rec {
+  pname = "persistent-nix-shell";
+  version = "0.1";
+  src = ../persistent-nix-shell;
+
+  phases = [ "buildPhase" "installPhase" ];
+
+  inherit zsh;
+
+  buildPhase = ''
+    substituteAll $src persistent-nix-shell
+  '';
+
+  installPhase = ''
+    install -m 0755 -D -t $out/bin \
+      persistent-nix-shell
+  '';
+}
diff --git a/persistent-nix-shell b/persistent-nix-shell
new file mode 100755
index 0000000..a17f6de
--- /dev/null
+++ b/persistent-nix-shell
@@ -0,0 +1,20 @@
+#!@zsh@/bin/zsh
+
+set -e
+
+gcrootsDir=${PWD}/.nix-gc-roots
+
+if [[ ${#@} -ge 1 ]]; then
+  shellFile=${1}
+  shift
+else
+  shellFile=${PWD}/shell.nix
+fi
+
+set -x
+mkdir -p ${gcrootsDir}
+nix-instantiate ${shellFile} --indirect --add-root ${gcrootsDir}/shell.drv
+nix-store --indirect --add-root ${gcrootsDir}/shell.dep --realise $(nix-store --query --references ${gcrootsDir}/shell.drv)
+set +x
+
+exec nix-shell $(readlink ${gcrootsDir}/shell.drv) ${@}