nix_2_3: drop

This has been marked insecure a while ago, as some CVEs have not been
backported. Even if *some* CVEs are fixed, we'd need **all** of them to
be, to get it back into the cache.

Not having it in the cache means, we can not test it in CI. This means
we can't make sure to actually support this version to evaluate Nixpkgs.

ci/default.nix

@@ -17,13 +17,7 @@ let
     else
       nixpkgs;
 
-  pkgs = import nixpkgs' {
+  pkgs = import nixpkgs' { inherit system; };
-    inherit system;
-    config = {
-      permittedInsecurePackages = [ "nix-2.3.18" ];
-    };
-    overlays = [ ];
-  };
 
   fmt =
     let

doc/release-notes/rl-2511.section.md

@@ -14,6 +14,10 @@
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
+- `nixVersions.nix_2_3` has been dropped because it was insecure and unmaintained.
+
+- The minimum version of Nix required to evaluate Nixpkgs has been raised from 2.3 to 2.18.
+
 - The `offrss` package was removed due to lack of upstream maintenance since 2012. It's recommended for users to migrate to another RSS reader
 
 - `base16-builder` node package has been removed due to lack of upstream maintenance.

lib/minver.nix

@@ -1,2 +1,2 @@
 # Expose the minimum required version for evaluating Nixpkgs
-"2.3.17"
+"2.18"

lib/tests/release.nix

@@ -2,16 +2,9 @@
   # The pkgs used for dependencies for the testing itself
   # Don't test properties of pkgs.lib, but rather the lib in the parent directory
   system ? builtins.currentSystem,
-  pkgs ?
+  pkgs ? import ../.. { inherit system; } // {
-    import ../.. {
+    lib = throw "pkgs.lib accessed, but the lib tests should use nixpkgs' lib path directly!";
-      inherit system;
+  },
-      config = {
-        permittedInsecurePackages = [ "nix-2.3.18" ];
-      };
-    }
-    // {
-      lib = throw "pkgs.lib accessed, but the lib tests should use nixpkgs' lib path directly!";
-    },
   # For testing someone may edit impure.nix to return cross pkgs, use `pkgsBuildBuild` directly so everything here works.
   pkgsBB ? pkgs.pkgsBuildBuild,
   nix ? pkgs-nixVersions.stable,

pkgs/by-name/ni/nixos-rebuild-ng/package.nix

@@ -121,9 +121,9 @@ python3Packages.buildPythonApplication rec {
         with_nix_stable = nixos-rebuild-ng.override {
           nix = nixVersions.stable;
         };
-        with_nix_2_3 = nixos-rebuild-ng.override {
+        with_nix_2_24 = nixos-rebuild-ng.override {
-          # oldest / minimum supported version in nixpkgs
+          # oldest supported version in nixpkgs
-          nix = nixVersions.nix_2_3;
+          nix = nixVersions.nix_2_24;
         };
         with_lix_latest = nixos-rebuild-ng.override {
           nix = lixPackageSets.latest.lix;

pkgs/tools/package-management/nix/common-autoconf.nix

@@ -21,7 +21,6 @@
 }@args:
 assert (hash == null) -> (src != null);
 let
-  atLeast224 = lib.versionAtLeast version "2.24pre";
   atLeast225 = lib.versionAtLeast version "2.25pre";
 in
 {
@@ -116,7 +115,7 @@ let
     ]
     ++ lib.optional stdenv.hostPlatform.isMusl "fortify";
 
-    nativeInstallCheckInputs = lib.optionals atLeast224 [
+    nativeInstallCheckInputs = [
       git
       man
     ];
@@ -129,21 +128,11 @@ let
       flex
       jq
     ]
-    ++ lib.optionals enableDocumentation (
+    ++ lib.optionals enableDocumentation [
-      if atLeast224 then
+      (lib.getBin lowdown-unsandboxed)
-        [
+      mdbook
-          (lib.getBin lowdown-unsandboxed)
+      mdbook-linkcheck
-          mdbook
+    ]
-          mdbook-linkcheck
-        ]
-      else
-        [
-          libxslt
-          libxml2
-          docbook_xsl_ns
-          docbook5
-        ]
-    )
     ++ lib.optionals stdenv.hostPlatform.isLinux [
       util-linuxMinimal
     ];
@@ -161,8 +150,6 @@ let
       gtest
       libarchive
       lowdown
-    ]
-    ++ lib.optionals atLeast224 [
       libgit2
       toml11
       rapidcheck
@@ -182,8 +169,6 @@ let
 
     propagatedBuildInputs = [
       boehmgc
-    ]
-    ++ lib.optionals atLeast224 [
       nlohmann_json
     ];
 
@@ -202,24 +187,7 @@ let
           chmod u+w $out/lib/*.so.*
           patchelf --set-rpath $out/lib:${lib.getLib stdenv.cc.cc}/lib $out/lib/libboost_thread.so.*
         ''}
-      ''
+      '';
-      +
-        # On all versions before c9f51e87057652db0013289a95deffba495b35e7, which
-        # removes config.nix entirely and is not present in 2.3.x, we need to
-        # patch around an issue where the Nix configure step pulls in the build
-        # system's bash and other utilities when cross-compiling.
-        lib.optionalString (stdenv.buildPlatform != stdenv.hostPlatform && !atLeast224) ''
-          mkdir tmp/
-          substitute corepkgs/config.nix.in tmp/config.nix.in \
-            --subst-var-by bash ${bash}/bin/bash \
-            --subst-var-by coreutils ${coreutils}/bin \
-            --subst-var-by bzip2 ${bzip2}/bin/bzip2 \
-            --subst-var-by gzip ${gzip}/bin/gzip \
-            --subst-var-by xz ${xz}/bin/xz \
-            --subst-var-by tar ${gnutar}/bin/tar \
-            --subst-var-by tr ${coreutils}/bin/tr
-          mv tmp/config.nix.in corepkgs/config.nix.in
-        '';
 
     configureFlags = [
       "--with-store-dir=${storeDir}"
@@ -233,7 +201,7 @@ let
     ++ lib.optionals stdenv.hostPlatform.isLinux [
       "--with-sandbox-shell=${busybox-sandbox-shell}/bin/busybox"
     ]
-    ++ lib.optionals (atLeast224 && stdenv.hostPlatform.isLinux && stdenv.hostPlatform.isStatic) [
+    ++ lib.optionals (stdenv.hostPlatform.isLinux && stdenv.hostPlatform.isStatic) [
       "--enable-embedded-sandbox-shell"
     ]
     ++
@@ -250,7 +218,7 @@ let
       # RISC-V support in progress https://github.com/seccomp/libseccomp/pull/50
       "--disable-seccomp-sandboxing"
     ]
-    ++ lib.optionals (atLeast224 && stdenv.cc.isGNU && !enableStatic) [
+    ++ lib.optionals (stdenv.cc.isGNU && !enableStatic) [
       "--enable-lto"
     ];
 
@@ -275,7 +243,7 @@ let
     installFlags = [ "sysconfdir=$(out)/etc" ];
 
     doInstallCheck = true;
-    installCheckTarget = if atLeast224 then "installcheck" else null;
+    installCheckTarget = "installcheck";
 
     # socket path becomes too long otherwise
     preInstallCheck =
@@ -288,10 +256,10 @@ let
         export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
       ''
       # See https://github.com/NixOS/nix/issues/5687
-      + lib.optionalString (atLeast224 && stdenv.hostPlatform.isDarwin) ''
+      + lib.optionalString (stdenv.hostPlatform.isDarwin) ''
         echo "exit 99" > tests/gc-non-blocking.sh
       '' # TODO: investigate why this broken
-      + lib.optionalString (atLeast224 && stdenv.hostPlatform.system == "aarch64-linux") ''
+      + lib.optionalString (stdenv.hostPlatform.system == "aarch64-linux") ''
         echo "exit 0" > tests/functional/flakes/show.sh
       ''
       + ''
@@ -299,7 +267,7 @@ let
         export MANPATH=$man/share/man:$MANPATH
       '';
 
-    separateDebugInfo = stdenv.hostPlatform.isLinux && (atLeast224 -> !enableStatic);
+    separateDebugInfo = stdenv.hostPlatform.isLinux && !enableStatic;
 
     enableParallelBuilding = true;
 

pkgs/tools/package-management/nix/default.nix

@@ -151,32 +151,6 @@ lib.makeExtensible (
   self:
   (
     {
-      nix_2_3 =
-        (commonAutoconf {
-          version = "2.3.18";
-          hash = "sha256-jBz2Ub65eFYG+aWgSI3AJYvLSghio77fWQiIW1svA9U=";
-          patches = [
-            patch-monitorfdhup
-          ];
-          self_attribute_name = "nix_2_3";
-          knownVulnerabilities = [
-            "CVE-2024-38531"
-            "CVE-2024-47174"
-            "CVE-2025-46415"
-            "CVE-2025-46416"
-            "CVE-2025-52991"
-            "CVE-2025-52992"
-            "CVE-2025-52993"
-          ];
-          maintainers = with lib.maintainers; [ flokli ];
-          teams = [ ];
-        }).overrideAttrs
-          {
-            # https://github.com/NixOS/nix/issues/10222
-            # spurious test/add.sh failures
-            enableParallelChecking = false;
-          };
-
       nix_2_24 = commonAutoconf {
         version = "2.24.15";
         hash = "sha256-GHqFHLxvRID2IEPUwIfRMp8epYQMFcvG9ogLzfWRbPc=";

pkgs/tools/package-management/nix/update-all.sh

@@ -11,9 +11,6 @@ nix_versions=$(nix eval --impure --json --expr "with import ./. { config.allowAl
 
 for name in $nix_versions; do
     minor_version=${name#nix_*_}
-    if [[ "$name" = "nix_2_3" ]]; then # not maintained by the nix team
-        continue
-    fi
 
     nix-update --override-filename "$SCRIPT_DIR/default.nix" --version-regex "(2\\.${minor_version}\..+)" --build --commit "nixVersions.$name"
 done
@@ -25,9 +22,6 @@ stable_version_trimmed=${stable_version_full%.*}
 
 for name in $nix_versions; do
     minor_version=${name#nix_*_}
-    if [[ "$name" = "nix_2_3" ]]; then # not maintained by the nix team
-        continue
-    fi
     if [[ "$name" = "nix_${stable_version_trimmed//./_}" ]]; then
         curl https://releases.nixos.org/nix/nix-$stable_version_full/fallback-paths.nix > "$NIXPKGS_DIR/nixos/modules/installer/tools/nix-fallback-paths.nix"
         # nix-update will commit the file if it has changed

pkgs/top-level/aliases.nix

@@ -1435,7 +1435,7 @@ mapAliases {
   nixFlakes = throw "'nixFlakes' has been renamed to/replaced by 'nixVersions.stable'"; # Converted to throw 2024-10-17
   nixStable = nixVersions.stable; # Added 2022-01-24
   nixUnstable = throw "nixUnstable has been removed. For bleeding edge (Nix master, roughly weekly updated) use nixVersions.git, otherwise use nixVersions.latest."; # Converted to throw 2024-04-22
-  nix_2_3 = nixVersions.nix_2_3;
+  nix_2_3 = throw "'nix_2_3' has been removed, because it was unmaintained and insecure."; # Converted to throw 2025-07-24
   nixfmt-rfc-style =
     if lib.oldestSupportedReleaseIsAtLeast 2511 then
       lib.warnOnInstantiate

pkgs/top-level/make-tarball.nix

@@ -3,13 +3,7 @@
   officialRelease,
   pkgs ? import nixpkgs.outPath { },
   nix ? pkgs.nix,
-  lib-tests ? import ../../lib/tests/release.nix {
+  lib-tests ? import ../../lib/tests/release.nix { inherit pkgs; },
-    pkgs = import nixpkgs.outPath {
-      config = {
-        permittedInsecurePackages = [ "nix-2.3.18" ];
-      };
-    };
-  },
 }:
 
 pkgs.releaseTools.sourceTarball {

pkgs/top-level/release.nix

@@ -113,20 +113,7 @@ let
 
     manual = pkgs.nixpkgs-manual.override { inherit nixpkgs; };
     metrics = import ./metrics.nix { inherit pkgs nixpkgs; };
-    lib-tests = import ../../lib/tests/release.nix {
+    lib-tests = import ../../lib/tests/release.nix { inherit pkgs; };
-      pkgs = import nixpkgs (
-        recursiveUpdate
-          (recursiveUpdate {
-            inherit system;
-            config.allowUnsupportedSystem = true;
-          } nixpkgsArgs)
-          {
-            config.permittedInsecurePackages = nixpkgsArgs.config.permittedInsecurePackages or [ ] ++ [
-              "nix-2.3.18"
-            ];
-          }
-      );
-    };
     pkgs-lib-tests = import ../pkgs-lib/tests { inherit pkgs; };
 
     darwin-tested =