initial commit

dev.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Enter the dev shell without re-fetching nixpkgs.
+#
+# flake.nix pins nixos-26.05. When the machine already has that revision in its
+# store (NixOS systems built from the same channel usually do), pointing the
+# input at the local path skips the tarball fetch entirely and makes
+# `nix develop` near-instant. Falls back to the pinned input otherwise.
+set -euo pipefail
+
+local_nixpkgs=$(nix registry list 2>/dev/null |
+	awk '$1 == "system" && $2 == "flake:nixpkgs" { print $3 }' |
+	sed 's/?.*//')
+
+args=()
+if [[ -n ${local_nixpkgs} && -d ${local_nixpkgs#path:} ]]; then
+	args=(--override-input nixpkgs "${local_nixpkgs}")
+fi
+
+exec nix develop "${args[@]}" --command "${@:-bash}"