diff --git a/pkgs/tools/package-management/nix/2_26/.version b/pkgs/tools/package-management/nix/2_26/.version
new file mode 100644
index 000000000000..7a25c70f90cf
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/.version
@@ -0,0 +1 @@
+2.26.0
diff --git a/pkgs/tools/package-management/nix/2_26/doc/manual/package.nix b/pkgs/tools/package-management/nix/2_26/doc/manual/package.nix
new file mode 100644
index 000000000000..f8133f2e1dd1
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/doc/manual/package.nix
@@ -0,0 +1,71 @@
+{ lib
+, mkMesonDerivation
+
+, meson
+, ninja
+, lowdown-unsandboxed
+, mdbook
+, mdbook-linkcheck
+, jq
+, python3
+, rsync
+, nix-cli
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-manual";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.difference
+    (fileset.unions [
+      ../../.version
+      # Too many different types of files to filter for now
+      ../../doc/manual
+      ./.
+    ])
+    # Do a blacklist instead
+    ../../doc/manual/package.nix;
+
+  # TODO the man pages should probably be separate
+  outputs = [ "out" "man" ];
+
+  # Hack for sake of the dev shell
+  passthru.externalNativeBuildInputs = [
+    meson
+    ninja
+    (lib.getBin lowdown-unsandboxed)
+    mdbook
+    mdbook-linkcheck
+    jq
+    python3
+    rsync
+  ];
+
+  nativeBuildInputs = finalAttrs.passthru.externalNativeBuildInputs ++ [
+    nix-cli
+  ];
+
+  preConfigure =
+    ''
+      chmod u+w ./.version
+      echo ${finalAttrs.version} > ./.version
+    '';
+
+  postInstall = ''
+    mkdir -p ''$out/nix-support
+    echo "doc manual ''$out/share/doc/nix/manual" >> ''$out/nix-support/hydra-build-products
+  '';
+
+  meta = {
+    platforms = lib.platforms.all;
+  };
+})
diff --git a/pkgs/tools/package-management/nix/2_26/packaging/components.nix b/pkgs/tools/package-management/nix/2_26/packaging/components.nix
new file mode 100644
index 000000000000..e1f661be8fbc
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/packaging/components.nix
@@ -0,0 +1,66 @@
+{
+  lib,
+  src,
+  officialRelease,
+}:
+
+scope:
+
+let
+  inherit (scope) callPackage;
+
+  baseVersion = lib.fileContents ../.version;
+
+  versionSuffix = lib.optionalString (!officialRelease) "pre";
+
+  fineVersionSuffix = lib.optionalString
+    (!officialRelease)
+    "pre${builtins.substring 0 8 (src.lastModifiedDate or src.lastModified or "19700101")}_${src.shortRev or "dirty"}";
+
+  fineVersion = baseVersion + fineVersionSuffix;
+in
+
+# This becomes the pkgs.nixComponents attribute set
+{
+  version = baseVersion + versionSuffix;
+  inherit versionSuffix;
+
+  nix-util = callPackage ../src/libutil/package.nix { };
+  nix-util-c = callPackage ../src/libutil-c/package.nix { };
+  nix-util-test-support = callPackage ../src/libutil-test-support/package.nix { };
+  nix-util-tests = callPackage ../src/libutil-tests/package.nix { };
+
+  nix-store = callPackage ../src/libstore/package.nix { };
+  nix-store-c = callPackage ../src/libstore-c/package.nix { };
+  nix-store-test-support = callPackage ../src/libstore-test-support/package.nix { };
+  nix-store-tests = callPackage ../src/libstore-tests/package.nix { };
+
+  nix-fetchers = callPackage ../src/libfetchers/package.nix { };
+  nix-fetchers-tests = callPackage ../src/libfetchers-tests/package.nix { };
+
+  nix-expr = callPackage ../src/libexpr/package.nix { };
+  nix-expr-c = callPackage ../src/libexpr-c/package.nix { };
+  nix-expr-test-support = callPackage ../src/libexpr-test-support/package.nix { };
+  nix-expr-tests = callPackage ../src/libexpr-tests/package.nix { };
+
+  nix-flake = callPackage ../src/libflake/package.nix { };
+  nix-flake-c = callPackage ../src/libflake-c/package.nix { };
+  nix-flake-tests = callPackage ../src/libflake-tests/package.nix { };
+
+  nix-main = callPackage ../src/libmain/package.nix { };
+  nix-main-c = callPackage ../src/libmain-c/package.nix { };
+
+  nix-cmd = callPackage ../src/libcmd/package.nix { };
+
+  nix-cli = callPackage ../src/nix/package.nix { version = fineVersion; };
+
+  nix-functional-tests = callPackage ../src/nix-functional-tests/package.nix { version = fineVersion; };
+
+  nix-manual = callPackage ../doc/manual/package.nix { version = fineVersion; };
+  nix-internal-api-docs = callPackage ../src/internal-api-docs/package.nix { version = fineVersion; };
+  nix-external-api-docs = callPackage ../src/external-api-docs/package.nix { version = fineVersion; };
+
+  nix-perl-bindings = callPackage ../src/perl/package.nix { };
+
+  nix-everything = callPackage ../packaging/everything.nix { };
+}
diff --git a/pkgs/tools/package-management/nix/2_26/packaging/everything.nix b/pkgs/tools/package-management/nix/2_26/packaging/everything.nix
new file mode 100644
index 000000000000..7ca878d8d535
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/packaging/everything.nix
@@ -0,0 +1,192 @@
+{
+  lib,
+  stdenv,
+  buildEnv,
+
+  nix-util,
+  nix-util-c,
+  nix-util-tests,
+
+  nix-store,
+  nix-store-c,
+  nix-store-tests,
+
+  nix-fetchers,
+  nix-fetchers-tests,
+
+  nix-expr,
+  nix-expr-c,
+  nix-expr-tests,
+
+  nix-flake,
+  nix-flake-c,
+  nix-flake-tests,
+
+  nix-main,
+  nix-main-c,
+
+  nix-cmd,
+
+  nix-cli,
+
+  nix-functional-tests,
+
+  nix-manual,
+  nix-internal-api-docs,
+  nix-external-api-docs,
+
+  nix-perl-bindings,
+
+  testers,
+  runCommand,
+}:
+
+let
+  libs = {
+    inherit
+      nix-util
+      nix-util-c
+      nix-store
+      nix-store-c
+      nix-fetchers
+      nix-expr
+      nix-expr-c
+      nix-flake
+      nix-flake-c
+      nix-main
+      nix-main-c
+      nix-cmd
+    ;
+  } // lib.optionalAttrs (!stdenv.hostPlatform.isStatic && stdenv.buildPlatform.canExecute stdenv.hostPlatform) {
+    # Currently fails in static build
+    inherit
+      nix-perl-bindings
+    ;
+  };
+
+  dev = stdenv.mkDerivation (finalAttrs: {
+    name = "nix-${nix-cli.version}-dev";
+    pname = "nix";
+    version = nix-cli.version;
+    dontUnpack = true;
+    dontBuild = true;
+    libs = map lib.getDev (lib.attrValues libs);
+    installPhase = ''
+      mkdir -p $out/nix-support
+      echo $libs >> $out/nix-support/propagated-build-inputs
+    '';
+    passthru = {
+      tests = {
+        pkg-config =
+          testers.hasPkgConfigModules {
+            package = finalAttrs.finalPackage;
+          };
+      };
+
+      # If we were to fully emulate output selection here, we'd confuse the Nix CLIs,
+      # because they rely on `drvPath`.
+      dev = finalAttrs.finalPackage.out;
+
+      libs = throw "`nix.dev.libs` is not meant to be used; use `nix.libs` instead.";
+    };
+    meta = {
+      pkgConfigModules = [
+        "nix-cmd"
+        "nix-expr"
+        "nix-expr-c"
+        "nix-fetchers"
+        "nix-flake"
+        "nix-flake-c"
+        "nix-main"
+        "nix-main-c"
+        "nix-store"
+        "nix-store-c"
+        "nix-util"
+        "nix-util-c"
+      ];
+    };
+  });
+  devdoc = buildEnv {
+    name = "nix-${nix-cli.version}-devdoc";
+    paths = [
+      nix-internal-api-docs
+      nix-external-api-docs
+    ];
+  };
+
+in
+(buildEnv {
+  name = "nix-${nix-cli.version}";
+  paths = [
+    nix-cli
+    nix-manual.man
+  ];
+
+  meta.mainProgram = "nix";
+}).overrideAttrs (finalAttrs: prevAttrs: {
+  doCheck = true;
+  doInstallCheck = true;
+
+  checkInputs = [
+    # Make sure the unit tests have passed
+    nix-util-tests.tests.run
+    nix-store-tests.tests.run
+    nix-expr-tests.tests.run
+    nix-fetchers-tests.tests.run
+    nix-flake-tests.tests.run
+
+    # Make sure the functional tests have passed
+    nix-functional-tests
+
+    # dev bundle is ok
+    # (checkInputs must be empty paths??)
+    (runCommand "check-pkg-config" { checked = dev.tests.pkg-config; } "mkdir $out")
+  ] ++ lib.optionals (!stdenv.hostPlatform.isStatic && stdenv.buildPlatform.canExecute stdenv.hostPlatform) [
+    # Perl currently fails in static build
+    # TODO: Split out tests into a separate derivation?
+    nix-perl-bindings
+  ];
+  passthru = prevAttrs.passthru // {
+    inherit (nix-cli) version;
+
+    /**
+      These are the libraries that are part of the Nix project. They are used
+      by the Nix CLI and other tools.
+
+      If you need to use these libraries in your project, we recommend to use
+      the `-c` C API libraries exclusively, if possible.
+
+      We also recommend that you build the complete package to ensure that the unit tests pass.
+      You could do this in CI, or by passing it in an unused environment variable. e.g in a `mkDerivation` call:
+
+      ```nix
+        buildInputs = [ nix.libs.nix-util-c nix.libs.nix-store-c ];
+        # Make sure the nix libs we use are ok
+        unusedInputsForTests = [ nix ];
+        disallowedReferences = nix.all;
+      ```
+     */
+    inherit libs;
+
+    tests = prevAttrs.passthru.tests or {} // {
+      # TODO: create a proper fixpoint and:
+      # pkg-config =
+      #   testers.hasPkgConfigModules {
+      #     package = finalPackage;
+      #   };
+    };
+
+    /**
+      A derivation referencing the `dev` outputs of the Nix libraries.
+     */
+    inherit dev;
+    inherit devdoc;
+    doc = nix-manual;
+    outputs = [ "out" "dev" "devdoc" "doc" ];
+    all = lib.attrValues (lib.genAttrs finalAttrs.passthru.outputs (outName: finalAttrs.finalPackage.${outName}));
+  };
+  meta = prevAttrs.meta // {
+    description = "The Nix package manager";
+    pkgConfigModules = dev.meta.pkgConfigModules;
+  };
+})
diff --git a/pkgs/tools/package-management/nix/2_26/source.json b/pkgs/tools/package-management/nix/2_26/source.json
new file mode 100644
index 000000000000..40acad769e09
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/source.json
@@ -0,0 +1,6 @@
+{
+    "owner": "NixOS",
+    "repo": "nix",
+    "rev": "717372382f75be6832c73ec5519e5d6b9aa5141b",
+    "hash": "sha256-0lFNh54gkDsdHOriOEHK6lr1rGRiP1mhNaCNm+6QspE="
+}
diff --git a/pkgs/tools/package-management/nix/2_26/src/external-api-docs/package.nix b/pkgs/tools/package-management/nix/2_26/src/external-api-docs/package.nix
new file mode 100644
index 000000000000..57c5138cfdb4
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/external-api-docs/package.nix
@@ -0,0 +1,56 @@
+{ lib
+, mkMesonDerivation
+
+, doxygen
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-external-api-docs";
+  inherit version;
+
+  workDir = ./.;
+  fileset =
+    let
+      cpp = fileset.fileFilter (file: file.hasExt "cc" || file.hasExt "h");
+    in
+    fileset.unions [
+      ./.version
+      ../../.version
+      ./meson.build
+      ./doxygen.cfg.in
+      ./README.md
+      # Source is not compiled, but still must be available for Doxygen
+      # to gather comments.
+      (cpp ../libexpr-c)
+      (cpp ../libflake-c)
+      (cpp ../libstore-c)
+      (cpp ../libutil-c)
+    ];
+
+  nativeBuildInputs = [
+    doxygen
+  ];
+
+  preConfigure =
+    ''
+      chmod u+w ./.version
+      echo ${finalAttrs.version} > ./.version
+    '';
+
+  postInstall = ''
+    mkdir -p ''${!outputDoc}/nix-support
+    echo "doc external-api-docs $out/share/doc/nix/external-api/html" >> ''${!outputDoc}/nix-support/hydra-build-products
+  '';
+
+  meta = {
+    platforms = lib.platforms.all;
+  };
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/internal-api-docs/package.nix b/pkgs/tools/package-management/nix/2_26/src/internal-api-docs/package.nix
new file mode 100644
index 000000000000..993a257a69f3
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/internal-api-docs/package.nix
@@ -0,0 +1,50 @@
+{ lib
+, mkMesonDerivation
+
+, doxygen
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-internal-api-docs";
+  inherit version;
+
+  workDir = ./.;
+  fileset = let
+    cpp = fileset.fileFilter (file: file.hasExt "cc" || file.hasExt "hh");
+  in fileset.unions [
+    ./.version
+    ../../.version
+    ./meson.build
+    ./doxygen.cfg.in
+    # Source is not compiled, but still must be available for Doxygen
+    # to gather comments.
+    (cpp ../.)
+  ];
+
+  nativeBuildInputs = [
+    doxygen
+  ];
+
+  preConfigure =
+    ''
+      chmod u+w ./.version
+      echo ${finalAttrs.version} > ./.version
+    '';
+
+  postInstall = ''
+    mkdir -p ''${!outputDoc}/nix-support
+    echo "doc internal-api-docs $out/share/doc/nix/internal-api/html" >> ''${!outputDoc}/nix-support/hydra-build-products
+  '';
+
+  meta = {
+    platforms = lib.platforms.all;
+  };
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libcmd/package.nix b/pkgs/tools/package-management/nix/2_26/src/libcmd/package.nix
new file mode 100644
index 000000000000..5cafb4dc100c
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libcmd/package.nix
@@ -0,0 +1,83 @@
+{ lib
+, stdenv
+, mkMesonLibrary
+
+, nix-util
+, nix-store
+, nix-fetchers
+, nix-expr
+, nix-flake
+, nix-main
+, editline
+, readline
+, lowdown
+, nlohmann_json
+
+# Configuration Options
+
+, version
+
+# Whether to enable Markdown rendering in the Nix binary.
+, enableMarkdown ? !stdenv.hostPlatform.isWindows
+
+# Which interactive line editor library to use for Nix's repl.
+#
+# Currently supported choices are:
+#
+# - editline (default)
+# - readline
+, readlineFlavor ? if stdenv.hostPlatform.isWindows then "readline" else "editline"
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-cmd";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    ({ inherit editline readline; }.${readlineFlavor})
+  ] ++ lib.optional enableMarkdown lowdown;
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-store
+    nix-fetchers
+    nix-expr
+    nix-flake
+    nix-main
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+    (lib.mesonEnable "markdown" enableMarkdown)
+    (lib.mesonOption "readline-flavor" readlineFlavor)
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libexpr-c/package.nix b/pkgs/tools/package-management/nix/2_26/src/libexpr-c/package.nix
new file mode 100644
index 000000000000..5047f3e2e9ab
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libexpr-c/package.nix
@@ -0,0 +1,53 @@
+{ lib
+, mkMesonLibrary
+
+, nix-store-c
+, nix-expr
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-expr-c";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "h") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-store-c
+    nix-expr
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libexpr-test-support/package.nix b/pkgs/tools/package-management/nix/2_26/src/libexpr-test-support/package.nix
new file mode 100644
index 000000000000..48118fa0c758
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libexpr-test-support/package.nix
@@ -0,0 +1,57 @@
+{ lib
+, mkMesonLibrary
+
+, nix-store-test-support
+, nix-expr
+, nix-expr-c
+
+, rapidcheck
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-util-test-support";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-store-test-support
+    nix-expr
+    nix-expr-c
+    rapidcheck
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libexpr-tests/package.nix b/pkgs/tools/package-management/nix/2_26/src/libexpr-tests/package.nix
new file mode 100644
index 000000000000..a4a3bb0e7ecd
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libexpr-tests/package.nix
@@ -0,0 +1,79 @@
+{ lib
+, buildPackages
+, stdenv
+, mkMesonExecutable
+
+, nix-expr
+, nix-expr-c
+, nix-expr-test-support
+
+, rapidcheck
+, gtest
+, runCommand
+
+# Configuration Options
+
+, version
+, resolvePath
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix-expr-tests";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    nix-expr
+    nix-expr-c
+    nix-expr-test-support
+    rapidcheck
+    gtest
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  passthru = {
+    tests = {
+      run = runCommand "${finalAttrs.pname}-run" {
+        meta.broken = !stdenv.hostPlatform.emulatorAvailable buildPackages;
+      } (lib.optionalString stdenv.hostPlatform.isWindows ''
+        export HOME="$PWD/home-dir"
+        mkdir -p "$HOME"
+      '' + ''
+        export _NIX_TEST_UNIT_DATA=${resolvePath ./data}
+        ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
+        touch $out
+      '');
+    };
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+    mainProgram = finalAttrs.pname + stdenv.hostPlatform.extensions.executable;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libexpr/package.nix b/pkgs/tools/package-management/nix/2_26/src/libexpr/package.nix
new file mode 100644
index 000000000000..3d5b78e35f2d
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libexpr/package.nix
@@ -0,0 +1,105 @@
+{ lib
+, stdenv
+, mkMesonLibrary
+
+, bison
+, flex
+, cmake # for resolving toml11 dep
+
+, nix-util
+, nix-store
+, nix-fetchers
+, boost
+, boehmgc
+, nlohmann_json
+, toml11
+
+# Configuration Options
+
+, version
+
+# Whether to use garbage collection for the Nix language evaluator.
+#
+# If it is disabled, we just leak memory, but this is not as bad as it
+# sounds so long as evaluation just takes places within short-lived
+# processes. (When the process exits, the memory is reclaimed; it is
+# only leaked *within* the process.)
+#
+# Temporarily disabled on Windows because the `GC_throw_bad_alloc`
+# symbol is missing during linking.
+, enableGC ? !stdenv.hostPlatform.isWindows
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-expr";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    ./primops/meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    ./lexer.l
+    ./parser.y
+    (fileset.difference
+      (fileset.fileFilter (file: file.hasExt "nix") ./.)
+      ./package.nix
+    )
+  ];
+
+  nativeBuildInputs = [
+    bison
+    flex
+    cmake
+  ];
+
+  buildInputs = [
+    toml11
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-store
+    nix-fetchers
+  ] ++ finalAttrs.passthru.externalPropagatedBuildInputs;
+
+  # Hack for sake of the dev shell
+  passthru.externalPropagatedBuildInputs = [
+    boost
+    nlohmann_json
+  ] ++ lib.optional enableGC boehmgc;
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+    (lib.mesonEnable "gc" enableGC)
+  ];
+
+  env = {
+    # Needed for Meson to find Boost.
+    # https://github.com/NixOS/nixpkgs/issues/86131.
+    BOOST_INCLUDEDIR = "${lib.getDev boost}/include";
+    BOOST_LIBRARYDIR = "${lib.getLib boost}/lib";
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libfetchers-tests/package.nix b/pkgs/tools/package-management/nix/2_26/src/libfetchers-tests/package.nix
new file mode 100644
index 000000000000..5336672a2221
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libfetchers-tests/package.nix
@@ -0,0 +1,77 @@
+{ lib
+, buildPackages
+, stdenv
+, mkMesonExecutable
+
+, nix-fetchers
+, nix-store-test-support
+
+, rapidcheck
+, gtest
+, runCommand
+
+# Configuration Options
+
+, version
+, resolvePath
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix-fetchers-tests";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    nix-fetchers
+    nix-store-test-support
+    rapidcheck
+    gtest
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  passthru = {
+    tests = {
+      run = runCommand "${finalAttrs.pname}-run" {
+        meta.broken = !stdenv.hostPlatform.emulatorAvailable buildPackages;
+      } (lib.optionalString stdenv.hostPlatform.isWindows ''
+        export HOME="$PWD/home-dir"
+        mkdir -p "$HOME"
+      '' + ''
+        export _NIX_TEST_UNIT_DATA=${resolvePath ./data}
+        ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
+        touch $out
+      '');
+    };
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+    mainProgram = finalAttrs.pname + stdenv.hostPlatform.extensions.executable;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libfetchers/package.nix b/pkgs/tools/package-management/nix/2_26/src/libfetchers/package.nix
new file mode 100644
index 000000000000..d4ca18555031
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libfetchers/package.nix
@@ -0,0 +1,55 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util
+, nix-store
+, nlohmann_json
+, libgit2
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-fetchers";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    libgit2
+  ];
+
+  propagatedBuildInputs = [
+    nix-store
+    nix-util
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libflake-c/package.nix b/pkgs/tools/package-management/nix/2_26/src/libflake-c/package.nix
new file mode 100644
index 000000000000..dcd6c4966097
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libflake-c/package.nix
@@ -0,0 +1,55 @@
+{ lib
+, mkMesonLibrary
+
+, nix-store-c
+, nix-expr-c
+, nix-flake
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-flake-c";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "h") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-expr-c
+    nix-store-c
+    nix-flake
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libflake-tests/package.nix b/pkgs/tools/package-management/nix/2_26/src/libflake-tests/package.nix
new file mode 100644
index 000000000000..51b68ad581ff
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libflake-tests/package.nix
@@ -0,0 +1,80 @@
+{ lib
+, buildPackages
+, stdenv
+, mkMesonExecutable
+
+, nix-flake
+, nix-flake-c
+, nix-expr-test-support
+
+, rapidcheck
+, gtest
+, runCommand
+
+# Configuration Options
+
+, version
+, resolvePath
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix-flake-tests";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    nix-flake
+    nix-flake-c
+    nix-expr-test-support
+    rapidcheck
+    gtest
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  passthru = {
+    tests = {
+      run = runCommand "${finalAttrs.pname}-run" {
+        meta.broken = !stdenv.hostPlatform.emulatorAvailable buildPackages;
+      } (lib.optionalString stdenv.hostPlatform.isWindows ''
+        export HOME="$PWD/home-dir"
+        mkdir -p "$HOME"
+      '' + ''
+        export _NIX_TEST_UNIT_DATA=${resolvePath ./data}
+        export NIX_CONFIG="extra-experimental-features = flakes"
+        ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
+        touch $out
+      '');
+    };
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+    mainProgram = finalAttrs.pname + stdenv.hostPlatform.extensions.executable;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libflake/package.nix b/pkgs/tools/package-management/nix/2_26/src/libflake/package.nix
new file mode 100644
index 000000000000..3fc96a20e58c
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libflake/package.nix
@@ -0,0 +1,54 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util
+, nix-store
+, nix-fetchers
+, nix-expr
+, nlohmann_json
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-flake";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-store
+    nix-util
+    nix-fetchers
+    nix-expr
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libmain-c/package.nix b/pkgs/tools/package-management/nix/2_26/src/libmain-c/package.nix
new file mode 100644
index 000000000000..b96901bb46bb
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libmain-c/package.nix
@@ -0,0 +1,57 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util-c
+, nix-store
+, nix-store-c
+, nix-main
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-main-c";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "h") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util-c
+    nix-store
+    nix-store-c
+    nix-main
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libmain/package.nix b/pkgs/tools/package-management/nix/2_26/src/libmain/package.nix
new file mode 100644
index 000000000000..9a5b9e8c2df0
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libmain/package.nix
@@ -0,0 +1,51 @@
+{ lib
+, mkMesonLibrary
+
+, openssl
+
+, nix-util
+, nix-store
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-main";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-store
+    openssl
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libstore-c/package.nix b/pkgs/tools/package-management/nix/2_26/src/libstore-c/package.nix
new file mode 100644
index 000000000000..c2413c3890d1
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libstore-c/package.nix
@@ -0,0 +1,53 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util-c
+, nix-store
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-store-c";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "h") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util-c
+    nix-store
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libstore-test-support/package.nix b/pkgs/tools/package-management/nix/2_26/src/libstore-test-support/package.nix
new file mode 100644
index 000000000000..5d3f41b3e8b9
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libstore-test-support/package.nix
@@ -0,0 +1,57 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util-test-support
+, nix-store
+, nix-store-c
+
+, rapidcheck
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-store-test-support";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util-test-support
+    nix-store
+    nix-store-c
+    rapidcheck
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libstore-tests/package.nix b/pkgs/tools/package-management/nix/2_26/src/libstore-tests/package.nix
new file mode 100644
index 000000000000..3acf4e25c2cc
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libstore-tests/package.nix
@@ -0,0 +1,95 @@
+{ lib
+, buildPackages
+, stdenv
+, mkMesonExecutable
+
+, nix-store
+, nix-store-c
+, nix-store-test-support
+, sqlite
+
+, rapidcheck
+, gtest
+, runCommand
+
+# Configuration Options
+
+, version
+, filesetToSource
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix-store-tests";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  # Hack for sake of the dev shell
+  passthru.externalBuildInputs = [
+    sqlite
+    rapidcheck
+    gtest
+  ];
+
+  buildInputs = finalAttrs.passthru.externalBuildInputs ++ [
+    nix-store
+    nix-store-c
+    nix-store-test-support
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  passthru = {
+    tests = {
+      run = let
+        # Some data is shared with the functional tests: they create it,
+        # we consume it.
+        data = filesetToSource {
+          root = ../..;
+          fileset = lib.fileset.unions [
+            ./data
+            ../../tests/functional/derivation
+          ];
+        };
+      in runCommand "${finalAttrs.pname}-run" {
+        meta.broken = !stdenv.hostPlatform.emulatorAvailable buildPackages;
+      } (lib.optionalString stdenv.hostPlatform.isWindows ''
+        export HOME="$PWD/home-dir"
+        mkdir -p "$HOME"
+      '' + ''
+        export _NIX_TEST_UNIT_DATA=${data + "/src/libstore-tests/data"}
+        ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
+        touch $out
+      '');
+    };
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+    mainProgram = finalAttrs.pname + stdenv.hostPlatform.extensions.executable;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libstore/package.nix b/pkgs/tools/package-management/nix/2_26/src/libstore/package.nix
new file mode 100644
index 000000000000..4fbaea4acc57
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libstore/package.nix
@@ -0,0 +1,96 @@
+{ lib
+, stdenv
+, mkMesonLibrary
+
+, unixtools
+, darwin
+
+, nix-util
+, boost
+, curl
+, aws-sdk-cpp
+, libseccomp
+, nlohmann_json
+, sqlite
+
+, busybox-sandbox-shell ? null
+
+# Configuration Options
+
+, version
+
+, embeddedSandboxShell ? stdenv.hostPlatform.isStatic
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-store";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    ./linux/meson.build
+    ./unix/meson.build
+    ./windows/meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "sb") ./.)
+    (fileset.fileFilter (file: file.hasExt "md") ./.)
+    (fileset.fileFilter (file: file.hasExt "sql") ./.)
+  ];
+
+  nativeBuildInputs =
+    lib.optional embeddedSandboxShell unixtools.hexdump;
+
+  buildInputs = [
+    boost
+    curl
+    sqlite
+  ] ++ lib.optional stdenv.hostPlatform.isLinux libseccomp
+    # There have been issues building these dependencies
+    ++ lib.optional stdenv.hostPlatform.isDarwin darwin.apple_sdk.libs.sandbox
+    ++ lib.optional (stdenv.hostPlatform == stdenv.buildPlatform && (stdenv.isLinux || stdenv.isDarwin))
+      aws-sdk-cpp
+  ;
+
+  propagatedBuildInputs = [
+    nix-util
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+    (lib.mesonEnable "seccomp-sandboxing" stdenv.hostPlatform.isLinux)
+    (lib.mesonBool "embedded-sandbox-shell" embeddedSandboxShell)
+  ] ++ lib.optionals stdenv.hostPlatform.isLinux [
+    (lib.mesonOption "sandbox-shell" "${busybox-sandbox-shell}/bin/busybox")
+  ];
+
+  env = {
+    # Needed for Meson to find Boost.
+    # https://github.com/NixOS/nixpkgs/issues/86131.
+    BOOST_INCLUDEDIR = "${lib.getDev boost}/include";
+    BOOST_LIBRARYDIR = "${lib.getLib boost}/lib";
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libutil-c/package.nix b/pkgs/tools/package-management/nix/2_26/src/libutil-c/package.nix
new file mode 100644
index 000000000000..f80e0b7f0a2a
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libutil-c/package.nix
@@ -0,0 +1,51 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-util-c";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+    (fileset.fileFilter (file: file.hasExt "h") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libutil-test-support/package.nix b/pkgs/tools/package-management/nix/2_26/src/libutil-test-support/package.nix
new file mode 100644
index 000000000000..a8a239717a68
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libutil-test-support/package.nix
@@ -0,0 +1,55 @@
+{ lib
+, mkMesonLibrary
+
+, nix-util
+, nix-util-c
+
+, rapidcheck
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-util-test-support";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-util-c
+    rapidcheck
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libutil-tests/package.nix b/pkgs/tools/package-management/nix/2_26/src/libutil-tests/package.nix
new file mode 100644
index 000000000000..28769e115224
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libutil-tests/package.nix
@@ -0,0 +1,78 @@
+{ lib
+, buildPackages
+, stdenv
+, mkMesonExecutable
+
+, nix-util
+, nix-util-c
+, nix-util-test-support
+
+, rapidcheck
+, gtest
+, runCommand
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix-util-tests";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    nix-util
+    nix-util-c
+    nix-util-test-support
+    rapidcheck
+    gtest
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  passthru = {
+    tests = {
+      run = runCommand "${finalAttrs.pname}-run" {
+        meta.broken = !stdenv.hostPlatform.emulatorAvailable buildPackages;
+      } (lib.optionalString stdenv.hostPlatform.isWindows ''
+        export HOME="$PWD/home-dir"
+        mkdir -p "$HOME"
+      '' + ''
+        export _NIX_TEST_UNIT_DATA=${./data}
+        ${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe finalAttrs.finalPackage}
+        touch $out
+      '');
+    };
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+    mainProgram = finalAttrs.pname + stdenv.hostPlatform.extensions.executable;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/libutil/package.nix b/pkgs/tools/package-management/nix/2_26/src/libutil/package.nix
new file mode 100644
index 000000000000..679872a75c59
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/libutil/package.nix
@@ -0,0 +1,81 @@
+{ lib
+, stdenv
+, mkMesonLibrary
+
+, boost
+, brotli
+, libarchive
+, libcpuid
+, libsodium
+, nlohmann_json
+, openssl
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonLibrary (finalAttrs: {
+  pname = "nix-util";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./widecharwidth
+    ./meson.build
+    ./meson.options
+    ./linux/meson.build
+    ./unix/meson.build
+    ./windows/meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  buildInputs = [
+    brotli
+    libsodium
+    openssl
+  ] ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid
+  ;
+
+  propagatedBuildInputs = [
+    boost
+    libarchive
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    #
+    # TODO: change release process to add `pre` in `.version`, remove it
+    # before tagging, and restore after.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+    (lib.mesonEnable "cpuid" stdenv.hostPlatform.isx86_64)
+  ];
+
+  env = {
+    # Needed for Meson to find Boost.
+    # https://github.com/NixOS/nixpkgs/issues/86131.
+    BOOST_INCLUDEDIR = "${lib.getDev boost}/include";
+    BOOST_LIBRARYDIR = "${lib.getLib boost}/lib";
+  };
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/nix/package.nix b/pkgs/tools/package-management/nix/2_26/src/nix/package.nix
new file mode 100644
index 000000000000..171621af9176
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/nix/package.nix
@@ -0,0 +1,105 @@
+{ lib
+, mkMesonExecutable
+
+, nix-store
+, nix-expr
+, nix-main
+, nix-cmd
+
+# Configuration Options
+
+, version
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonExecutable (finalAttrs: {
+  pname = "nix";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions ([
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+
+    # Symbolic links to other dirs
+    ## exes
+    ./build-remote
+    ./doc
+    ./nix-build
+    ./nix-channel
+    ./nix-collect-garbage
+    ./nix-copy-closure
+    ./nix-env
+    ./nix-instantiate
+    ./nix-store
+    ## dirs
+    ./scripts
+    ../../scripts
+    ./misc
+    ../../misc
+
+    # Doc nix files for --help
+    ../../doc/manual/generate-manpage.nix
+    ../../doc/manual/utils.nix
+    ../../doc/manual/generate-settings.nix
+    ../../doc/manual/generate-store-info.nix
+
+    # Other files to be included as string literals
+    ../nix-channel/unpack-channel.nix
+    ../nix-env/buildenv.nix
+    ./get-env.sh
+    ./help-stores.md
+    ../../doc/manual/source/store/types/index.md.in
+    ./profiles.md
+    ../../doc/manual/source/command-ref/files/profiles.md
+
+    # Files
+  ] ++ lib.concatMap
+    (dir: [
+      (fileset.fileFilter (file: file.hasExt "cc") dir)
+      (fileset.fileFilter (file: file.hasExt "hh") dir)
+      (fileset.fileFilter (file: file.hasExt "md") dir)
+    ])
+    [
+      ./.
+      ../build-remote
+      ../nix-build
+      ../nix-channel
+      ../nix-collect-garbage
+      ../nix-copy-closure
+      ../nix-env
+      ../nix-instantiate
+      ../nix-store
+    ]
+  );
+
+  buildInputs = [
+    nix-store
+    nix-expr
+    nix-main
+    nix-cmd
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/pkgs/tools/package-management/nix/2_26/src/perl/package.nix b/pkgs/tools/package-management/nix/2_26/src/perl/package.nix
new file mode 100644
index 000000000000..5ee0df13c9d1
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/src/perl/package.nix
@@ -0,0 +1,76 @@
+{ lib
+, stdenv
+, mkMesonDerivation
+, pkg-config
+, perl
+, perlPackages
+, nix-store
+, version
+, curl
+, bzip2
+, libsodium
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+perl.pkgs.toPerlModule (mkMesonDerivation (finalAttrs: {
+  pname = "nix-perl";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions ([
+    ./.version
+    ../../.version
+    ./MANIFEST
+    ./lib
+    ./meson.build
+    ./meson.options
+  ] ++ lib.optionals finalAttrs.doCheck [
+    ./.yath.rc.in
+    ./t
+  ]);
+
+  nativeBuildInputs = [
+    pkg-config
+    perl
+    curl
+  ];
+
+  buildInputs = [
+    nix-store
+  ] ++ finalAttrs.passthru.externalBuildInputs;
+
+  # Hack for sake of the dev shell
+  passthru.externalBuildInputs = [
+    bzip2
+    libsodium
+  ];
+
+  # `perlPackages.Test2Harness` is marked broken for Darwin
+  doCheck = !stdenv.isDarwin;
+
+  nativeCheckInputs = [
+    perlPackages.Test2Harness
+  ];
+
+  preConfigure =
+    # "Inline" .version so its not a symlink, and includes the suffix
+    ''
+      chmod u+w .version
+      echo ${finalAttrs.version} > .version
+    '';
+
+  mesonFlags = [
+    (lib.mesonOption "dbi_path" "${perlPackages.DBI}/${perl.libPrefix}")
+    (lib.mesonOption "dbd_sqlite_path" "${perlPackages.DBDSQLite}/${perl.libPrefix}")
+    (lib.mesonEnable "tests" finalAttrs.doCheck)
+  ];
+
+  mesonCheckFlags = [
+    "--print-errorlogs"
+  ];
+
+  strictDeps = false;
+}))
diff --git a/pkgs/tools/package-management/nix/2_26/tests/functional/package.nix b/pkgs/tools/package-management/nix/2_26/tests/functional/package.nix
new file mode 100644
index 000000000000..d1582b05d145
--- /dev/null
+++ b/pkgs/tools/package-management/nix/2_26/tests/functional/package.nix
@@ -0,0 +1,103 @@
+{ lib
+, stdenv
+, mkMesonDerivation
+
+, meson
+, ninja
+, pkg-config
+
+, jq
+, git
+, mercurial
+, util-linux
+
+, nix-store
+, nix-expr
+, nix-cli
+
+, busybox-sandbox-shell ? null
+
+# Configuration Options
+
+, pname ? "nix-functional-tests"
+, version
+
+# For running the functional tests against a different pre-built Nix.
+, test-daemon ? null
+}:
+
+let
+  inherit (lib) fileset;
+in
+
+mkMesonDerivation (finalAttrs: {
+  inherit pname version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../scripts/nix-profile.sh.in
+    ../../.version
+    ../../tests/functional
+    ./.
+  ];
+
+  # Hack for sake of the dev shell
+  passthru.externalNativeBuildInputs = [
+    meson
+    ninja
+    pkg-config
+
+    jq
+    git
+    mercurial
+  ] ++ lib.optionals stdenv.hostPlatform.isLinux [
+    # For various sandboxing tests that needs a statically-linked shell,
+    # etc.
+    busybox-sandbox-shell
+    # For Overlay FS tests need `mount`, `umount`, and `unshare`.
+    # For `script` command (ensuring a TTY)
+    # TODO use `unixtools` to be precise over which executables instead?
+    util-linux
+  ];
+
+  nativeBuildInputs = finalAttrs.passthru.externalNativeBuildInputs ++ [
+    nix-cli
+  ];
+
+  buildInputs = [
+    nix-store
+    nix-expr
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../../.version
+    ''
+    # TEMP hack for Meson before make is gone, where
+    # `src/nix-functional-tests` is during the transition a symlink and
+    # not the actual directory directory.
+    + ''
+      cd $(readlink -e $PWD)
+      echo $PWD | grep tests/functional
+    '';
+
+  mesonCheckFlags = [
+    "--print-errorlogs"
+  ];
+
+  doCheck = true;
+
+  installPhase = ''
+    mkdir $out
+  '';
+
+  meta = {
+    platforms = lib.platforms.unix;
+  };
+
+} // lib.optionalAttrs (test-daemon != null) {
+  NIX_DAEMON_PACKAGE = test-daemon;
+})