From e6f9574bb8a70ab10b36a9db33ac8ca1c1113ec6 Mon Sep 17 00:00:00 2001
From: atagen <boss@atagen.co>
Date: Tue, 18 Nov 2025 13:54:09 +1100
Subject: [PATCH] create setup hook

---
 default.nix      | 20 ++++++++++----------
 flake.nix        |  1 +
 unset-nix-env.sh | 18 ++++++++++++++++++
 3 files changed, 29 insertions(+), 10 deletions(-)
 create mode 100644 unset-nix-env.sh

diff --git a/default.nix b/default.nix
index 58adfa0..a308df5 100644
--- a/default.nix
+++ b/default.nix
@@ -32,16 +32,16 @@ stdenv.mkDerivation {
     ++ packages;
 
   buildCommand = ''
-    # unset all nix-related variables
+    # unset all nix-related and generic session variables
     unset SHELL configureFlags mesonFlags shell depsHostHost STRINGS depsTargetTarget stdenv \
-      builder PWD SOURCE_DATE_EPOCH enableParallelInstalling CXX TEMPDIR system HOST_PATH \
-      enableParallelBuilding doInstallCheck buildCommandPath enableParallelChecking LS_COLORS \
-      depsTargetTargetPropagated cmakeFlakes outputs TMPDIR LD READELF doCheck \
-      depsBuildBuild SIZE propagatedNativeBuildInputs strictDeps AR AS TEMP SHLVL NM \
-      patches passAsFile buildInputs SSL_CERT_FILE depsBuildTarget OBJCOPY STRIP TMP OBJDUMP propagatedBuildInputs \
-      CC __ETC_PROFILE_SOURCED depsBuildTargetPropagated depsBuildBuildPropagated CONFIG_SHELL __structuredAttrs \
-      RANLIB nativeBuildInputs name depsHostHostPropagated TEST TZ HOME GZIP_NO_TIMESTAMPS \
-      cmakeFlags TERM buildCommand preferLocalBuild _
+    	builder PWD SOURCE_DATE_EPOCH enableParallelInstalling CXX TEMPDIR system HOST_PATH \
+    	enableParallelBuilding doInstallCheck buildCommandPath enableParallelChecking LS_COLORS \
+    	depsTargetTargetPropagated cmakeFlakes outputs TMPDIR LD READELF doCheck \
+    	depsBuildBuild SIZE propagatedNativeBuildInputs strictDeps AR AS TEMP SHLVL NM \
+    	patches passAsFile buildInputs SSL_CERT_FILE depsBuildTarget OBJCOPY STRIP TMP OBJDUMP propagatedBuildInputs \
+    	CC __ETC_PROFILE_SOURCED depsBuildTargetPropagated depsBuildBuildPropagated CONFIG_SHELL __structuredAttrs \
+    	RANLIB nativeBuildInputs name depsHostHostPropagated TEST TZ HOME GZIP_NO_TIMESTAMPS \
+    	cmakeFlags TERM buildCommand preferLocalBuild
     unset "''${!NIX_@}"
     # create export commands for the rest
     envs="$(env | sed 's/^/export /' -)"
@@ -49,7 +49,7 @@ stdenv.mkDerivation {
     printf '${script}' > $out
     echo "$envs" >> $out 
     echo 'exec $SHELL' >> $out
-    # required here
+    # only required here
     sed -i 's/^export out=.*$//' $out
     # inserted by env cmd
     sed -i 's/^export _=.*$//' $out
diff --git a/flake.nix b/flake.nix
index dc66487..c966912 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,5 +3,6 @@
     { self }:
     {
       mkShell = { pkgs, ... }@vars: import ./default.nix vars;
+      hook = ./unset-nix-env.sh;
     };
 }
diff --git a/unset-nix-env.sh b/unset-nix-env.sh
new file mode 100644
index 0000000..243c709
--- /dev/null
+++ b/unset-nix-env.sh
@@ -0,0 +1,18 @@
+unsetNixEnv () {
+	# unset all nix-related and generic session variables
+	unset SHELL configureFlags mesonFlags shell depsHostHost STRINGS depsTargetTarget stdenv \
+		builder PWD SOURCE_DATE_EPOCH enableParallelInstalling CXX TEMPDIR system HOST_PATH \
+		enableParallelBuilding doInstallCheck buildCommandPath enableParallelChecking LS_COLORS \
+		depsTargetTargetPropagated cmakeFlakes TMPDIR LD READELF doCheck \
+		depsBuildBuild SIZE propagatedNativeBuildInputs strictDeps AR AS TEMP SHLVL NM \
+		patches passAsFile buildInputs SSL_CERT_FILE depsBuildTarget OBJCOPY STRIP TMP OBJDUMP propagatedBuildInputs \
+		CC __ETC_PROFILE_SOURCED depsBuildTargetPropagated depsBuildBuildPropagated CONFIG_SHELL __structuredAttrs \
+		RANLIB nativeBuildInputs name depsHostHostPropagated TEST TZ HOME GZIP_NO_TIMESTAMPS \
+		cmakeFlags TERM buildCommand preferLocalBuild buildPhase phases shellHook NIX_CC \
+		NIX_STORE NIX_LDFLAGS NIX_BINTOOLS NIX_CFLAGS_COMPILE NIX_ENFORCE_NO_NATIVE NIX_HARDENING_ENABLE \
+		NIX_BUILD_CORES
+	unset "''${!NIX_BINTOOLS@}"
+	unset "''${!NIX_CC@}"
+}
+
+postHooks+=(unsetNixEnv)