refactor: Move nixpkgs attribute to `third_party.nixpkgs` r/2470

Please read b/108 to make sense of this.

This gets rid of the explicit list of exposed packages from nixpkgs,
and instead makes the entire package set available at
`third_party.nixpkgs`.

To accommodate this, a LOT of things have to be very slightly shuffled
around. Some of this was done in already submitted CLs, but this
change is unfortunately still quite noisy.

Pay extra attention to:

* overlay-like functionality that was partially moved to actual
  overlays (partially as in, the minimum required to get a green
  build)

* modified uses of the package set path, esp. in NixOS systems

Special notes:

* xanthous has been disabled in CI because of issues with the Haskell
  overlay
* //third_party/nix has been disabled because of other unclear
  dependency issues

Both of these will be tackled in a followup CL.

Change-Id: I2f9c60a4d275fdb5209264be0addfd7e06c53118
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2910
Reviewed-by: glittershark <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI

46 files changed, 278 insertions, 490 deletions

diff --git a/default.nix b/default.nix
index 15224b9cab..ee22077574 100644
--- a/default.nix
+++ b/default.nix
@@ -19,11 +19,11 @@ let
     inherit depot;
 
     # Expose lib attribute to packages.
-    inherit (depot) lib;
+    inherit (depot.third_party.nixpkgs) lib;
 
     # Pass third_party as 'pkgs' (for compatibility with external
     # imports for certain subdirectories)
-    pkgs = depot.third_party;
+    pkgs = depot.third_party.nixpkgs;
   };
 
   readTree' = import ./nix/readTree {};
@@ -75,9 +75,6 @@ in fix(self: {
   __readTree = [];
   config = config self;
 
-  # Elevate 'lib' from nixpkgs
-  lib = import (self.third_party.nixpkgsSrc + "/lib");
-
   # Expose readTree for downstream repo consumers.
   readTree = {
     __functor = x: (readTree' x.config);
@@ -97,6 +94,9 @@ in fix(self: {
     # generate pipelines because that also leads to infinite
     # recursion.
     ops = self.ops // { pipelines = null; };
+
+    # remove nixpkgs from the set, for obvious reasons.
+    third_party = self.third_party // { nixpkgs = null; };
   });
 }
 
diff --git a/fun/idual/default.nix b/fun/idual/default.nix
index 1ac87ab47f..877ab7d392 100644
--- a/fun/idual/default.nix
+++ b/fun/idual/default.nix
@@ -1,7 +1,7 @@
-{ pkgs, lib, ... }:
+{ depot, pkgs, lib, ... }:
 
 let
-  inherit (pkgs) python python3 python3Packages;
+  inherit (pkgs) python3 python3Packages;
 
   opts = {
     pname   = "idualctl";
@@ -9,12 +9,12 @@ let
     src     = ./.;
 
     propagatedBuildInputs = [
-      python.broadlink
+      depot.third_party.python.broadlink
     ];
   };
   package = python3Packages.buildPythonPackage opts;
   script  = python3Packages.buildPythonApplication opts;
-in {
+in depot.nix.utils.drvTargets {
   inherit script;
   python  = python3.withPackages (_: [ package ]);
   setAlarm = pkgs.writeShellScriptBin "set-alarm" ''
diff --git a/ops/nixos/default.nix b/ops/nixos/default.nix
index fc3508b529..8be700b104 100644
--- a/ops/nixos/default.nix
+++ b/ops/nixos/default.nix
@@ -8,9 +8,7 @@
 # situation.
 { depot, lib, pkgs, ... }@args:
 
-let
-  inherit (lib) findFirst isAttrs;
-  nixos = import "${depot.third_party.nixpkgsSrc}/nixos";
+let inherit (lib) findFirst isAttrs;
 in rec {
   whitby = import ./whitby/default.nix args;
 
@@ -25,7 +23,7 @@ in rec {
     };
   };
 
-  nixosFor = configuration: (nixos {
+  nixosFor = configuration: (depot.third_party.nixos {
     configuration = { ... }: {
       imports = [
         baseModule
diff --git a/ops/nixos/whitby/default.nix b/ops/nixos/whitby/default.nix
index 3c1c1f14bf..394b79c21b 100644
--- a/ops/nixos/whitby/default.nix
+++ b/ops/nixos/whitby/default.nix
@@ -1,10 +1,8 @@
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 let
   inherit (builtins) listToAttrs;
   inherit (lib) range;
-
-  nixpkgs = import depot.third_party.nixpkgsSrc {};
 in lib.fix(self: {
   imports = [
     "${depot.depotPath}/ops/nixos/clbot.nix"
@@ -27,7 +25,7 @@ in lib.fix(self: {
     "${depot.depotPath}/ops/nixos/www/todo.tvl.fyi.nix"
     "${depot.depotPath}/ops/nixos/www/tvl.fyi.nix"
     "${depot.depotPath}/ops/nixos/www/wigglydonke.rs.nix"
-    "${depot.third_party.nixpkgsSrc}/nixos/modules/services/web-apps/gerrit.nix"
+    "${pkgs.path}/nixos/modules/services/web-apps/gerrit.nix"
   ];
 
   hardware = {
@@ -140,14 +138,14 @@ in lib.fix(self: {
   # Generate an immutable /etc/resolv.conf from the nameserver settings
   # above (otherwise DHCP overwrites it):
   environment.etc."resolv.conf" = with lib; {
-    source = depot.third_party.writeText "resolv.conf" ''
+    source = pkgs.writeText "resolv.conf" ''
       ${concatStringsSep "\n" (map (ns: "nameserver ${ns}") self.networking.nameservers)}
       options edns0
     '';
   };
 
   # Disable background git gc system-wide, as it has a tendency to break CI.
-  environment.etc."gitconfig".source = depot.third_party.writeText "gitconfig" ''
+  environment.etc."gitconfig".source = pkgs.writeText "gitconfig" ''
     [gc]
     autoDetach = false
   '';
@@ -304,7 +302,7 @@ in lib.fix(self: {
     bindAddress = "localhost";
   };
 
-  environment.systemPackages = with nixpkgs; [
+  environment.systemPackages = with pkgs; [
     bb
     curl
     emacs-nox
@@ -332,7 +330,7 @@ in lib.fix(self: {
   # Regularly back up whitby to Google Cloud Storage.
   systemd.services.restic = {
     description = "Backups to Google Cloud Storage";
-    script = "${nixpkgs.restic}/bin/restic backup /var/lib/gerrit /var/backup/postgresql";
+    script = "${pkgs.restic}/bin/restic backup /var/lib/gerrit /var/backup/postgresql";
 
     environment = {
       GOOGLE_PROJECT_ID = "tazjins-infrastructure";
@@ -369,7 +367,7 @@ in lib.fix(self: {
     users.tazjin = {
       isNormalUser = true;
       extraGroups = [ "git" "wheel" ];
-      shell = nixpkgs.fish;
+      shell = pkgs.fish;
       openssh.authorizedKeys.keys = depot.users.tazjin.keys.all;
     };
 
diff --git a/third_party/default.nix b/third_party/default.nix
index 774e634f9c..0b1e94c7f8 100644
--- a/third_party/default.nix
+++ b/third_party/default.nix
@@ -1,73 +1,23 @@
-# This file controls the import of external dependencies (i.e.
-# third-party code) into my package tree.
+# This file defines the root of all external dependency imports (i.e.
+# third-party code) in the TVL package tree.
 #
-# This includes *all packages needed from nixpkgs*.
-{ ... }:
-
-let
-  # Tracking nixos-unstable as of 2021-03-25.
-  nixpkgsCommit = "60dd94fb7e01a8288f6638eee71d7cb354c49327";
-  nixpkgsSrc = fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/${nixpkgsCommit}.tar.gz";
-    sha256 = "0skdwk9bdld295kzrymirs8xrzycqmhsclaz8s18jhcz75hb8sk3";
-  };
-  nixpkgs = import nixpkgsSrc {
-    config.allowUnfree = true;
-    config.allowBroken = true;
-
-    # Lutris depends on p7zip, which is considered insecure.
-    config.permittedInsecurePackages = [
-      "p7zip-16.02"
-    ];
-  };
-
-  # Tracking nixos-20.09 as of 2021-03-25.
-  stableCommit = "223d0d733a66b46504ea6b4c15f88b7cc4db58fb";
-  stableNixpkgsSrc = fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/${stableCommit}.tar.gz";
-    sha256 = "073327ris0frqa3kpid3nsjr9w8yx2z83xpsc24w898mrs9r7d5v";
-  };
-  stableNixpkgs = import stableNixpkgsSrc {};
-
-  exposed = import ./nixpkgs-exposed/exposed { inherit nixpkgs stableNixpkgs; };
-
-in exposed.lib.fix(self: exposed // {
-  callPackage = nixpkgs.lib.callPackageWith self;
-
-  # Provide the source code of nixpkgs, but do not provide an imported
-  # version of it.
-  inherit nixpkgsCommit nixpkgsSrc stableNixpkgsSrc;
-
-  # Expose upstream attributes so they can be overridden in readTree nodes
-  originals = {
-    inherit (nixpkgs) gtest openldap go grpc notmuch rr;
-    inherit (stableNixpkgs) git tdlib;
-    ffmpeg = nixpkgs.ffmpeg-full;
-    telega = stableNixpkgs.emacsPackages.telega;
-
-  };
-
-  # Use LLVM 11
-  llvmPackages = nixpkgs.llvmPackages_11;
-  clangStdenv = nixpkgs.llvmPackages_11.stdenv;
-  stdenv = nixpkgs.llvmPackages_11.stdenv;
-
-  clang-tools = (nixpkgs.clang-tools.override {
-    llvmPackages = nixpkgs.llvmPackages_11;
-  });
-
-  # Provide Emacs 27
-  #
-  # The assert exists because the name of the attribute is unversioned
-  # (which is different from previous versions).
-  emacs27 = assert ((exposed.lib.versions.major nixpkgs.emacs.version) == "27");
-    nixpkgs.emacs.overrideAttrs(old: {
-      configureFlags = old.configureFlags ++ [ "--with-cairo" ];
-    });
-
-  emacs27-nox = assert ((exposed.lib.versions.major nixpkgs.emacs.version) == "27");
-    nixpkgs.emacs-nox;
-
-  # Make NixOS available
-  nixos = import "${nixpkgsSrc}/nixos";
-})
+# There are two categories of third-party programs:
+#
+# 1) Programs in nixpkgs, the NixOS package set. For these, you might
+#    want to look at //third_party/nixpkgs (for the package set
+#    imports) and //third_party/overlays (for modifications in these
+#    imported package sets).
+#
+# 2) Third-party software packaged in this repository. This is all
+#    other folders below //third_party, other than the ones mentioned
+#    above.
+
+{ pkgs, ... }:
+
+{
+  # Expose a partially applied NixOS, expecting an attribute set with
+  # a `configuration` key. Exposing it like this makes it possible to
+  # modify some of the base configuration used by NixOS. passed to
+  # this.
+  nixos = import "${pkgs.path}/nixos";
+}
diff --git a/third_party/ffmpeg/default.nix b/third_party/ffmpeg/default.nix
deleted file mode 100644
index e1b4d759da..0000000000
--- a/third_party/ffmpeg/default.nix
+++ /dev/null
@@ -1,12 +0,0 @@
-{ pkgs, ... }:
-
-pkgs.originals.ffmpeg.overrideAttrs(old: {
-  buildInputs = old.buildInputs ++ [
-    pkgs.cudatoolkit.out
-  ];
-
-  configureFlags = old.configureFlags ++ [
-    "--enable-libnpp"
-    "--enable-nonfree"
-  ];
-})
diff --git a/third_party/git/default.nix b/third_party/git/default.nix
index 26ea911a59..05766a8e6b 100644
--- a/third_party/git/default.nix
+++ b/third_party/git/default.nix
@@ -1,15 +1,13 @@
 # Use the upstream git derivation (there's a lot of stuff happening in
 # there!) and just override the source:
-{ depot, ... }:
+{ pkgs, ... }:
 
-with depot.third_party;
-
-(originals.git.overrideAttrs(_: {
+(pkgs.git.overrideAttrs(_: {
   version = "2.29.2";
   src = ./.;
   doInstallCheck = false;
   preConfigure = ''
-    ${autoconf}/bin/autoreconf -i
+    ${pkgs.autoconf}/bin/autoreconf -i
   '';
 })).override {
   sendEmailSupport = true;
diff --git a/third_party/grpc/default.nix b/third_party/grpc/default.nix
index ad34425e8f..87ae5d7a32 100644
--- a/third_party/grpc/default.nix
+++ b/third_party/grpc/default.nix
@@ -1,7 +1,7 @@
-{ pkgs, ... }:
+{ depot, pkgs, ... }:
 
-(pkgs.originals.grpc.override {
-  protobuf = pkgs.protobuf;
+(pkgs.grpc.override {
+  protobuf = depot.third_party.protobuf;
   stdenv = pkgs.llvmPackages.libcxxStdenv;
 }).overrideAttrs(orig: rec {
   version = "1.30.0";
diff --git a/third_party/gtest/default.nix b/third_party/gtest/default.nix
index 5ca8080b52..f320c29d23 100644
--- a/third_party/gtest/default.nix
+++ b/third_party/gtest/default.nix
@@ -1,6 +1,6 @@
 { pkgs, ... }:
 
-(pkgs.originals.gtest.override {
+(pkgs.gtest.override {
   stdenv = pkgs.llvmPackages.libcxxStdenv;
 }).overrideAttrs(_: {
   src = pkgs.fetchFromGitHub {
diff --git a/third_party/nix/default.nix b/third_party/nix/default.nix
index b48551cff0..d3adabe2bd 100644
--- a/third_party/nix/default.nix
+++ b/third_party/nix/default.nix
@@ -1,5 +1,6 @@
 args@{
-  pkgs ? (import ../.. {}).third_party
+  depot ? (import ../.. {})
+, pkgs ? depot.third_party.nixpkgs
 , lib
 , buildType ? "release"
 , depotPath ? ../..
@@ -43,10 +44,11 @@ let
   protoSrcs = pkgs.runCommand "nix-proto-srcs" {} ''
     export PROTO_SRCS=${./src/proto}
     mkdir -p $out/libproto
-    ${pkgs.protobuf}/bin/protoc -I=$PROTO_SRCS \
+    ${depot.third_party.protobuf}/bin/protoc -I=$PROTO_SRCS \
       --cpp_out=$out/libproto \
-      --plugin=protoc-gen-grpc=${pkgs.grpc}/bin/grpc_cpp_plugin --grpc_out=$out/libproto \
-      $PROTO_SRCS/*.proto
+      --plugin=protoc-gen-grpc=${depot.third_party.grpc}/bin/grpc_cpp_plugin \
+        --grpc_out=$out/libproto \
+        $PROTO_SRCS/*.proto
   '';
 
   # Derivation for busybox that just has the `busybox` binary in bin/, not all
@@ -73,7 +75,6 @@ in lib.fix (self: pkgs.llvmPackages.libcxxStdenv.mkDerivation {
 
  # TODO(tazjin): Some of these might only be required for native inputs
   buildInputs = with pkgs; [
-    abseil_cpp
     aws-s3-cpp
     brotli
     bzip2
@@ -81,16 +82,18 @@ in lib.fix (self: pkgs.llvmPackages.libcxxStdenv.mkDerivation {
     curl
     editline
     flex
-    glog
-    grpc
     libseccomp
     libsodium
     systemd.dev
     openssl
-    protobuf
     sqlite
     xz
-  ];
+  ] ++ (with depot.third_party; [
+    abseil_cpp
+    glog
+    grpc
+    protobuf
+  ]);
 
   doCheck = false;
   doInstallCheck = true;
@@ -99,8 +102,8 @@ in lib.fix (self: pkgs.llvmPackages.libcxxStdenv.mkDerivation {
   dontStrip = true;
 
   installCheckInputs = with pkgs; [
+    depot.third_party.gtest
     fd
-    gtest
     rapidcheck
   ];
 
@@ -185,6 +188,9 @@ in lib.fix (self: pkgs.llvmPackages.libcxxStdenv.mkDerivation {
   # TODO(tazjin): integration test setup?
   # TODO(tazjin): docs generation?
 
+  # TODO(tazjin): Sort out after CL/2910 lands
+  meta.ci = false;
+
   passthru = {
     build-shell = self.overrideAttrs (up: rec {
       run_clang_tidy = pkgs.writeShellScriptBin "run-clang-tidy" ''
diff --git a/third_party/nix/test-vm.nix b/third_party/nix/test-vm.nix
index 8f77441b7d..550537679c 100644
--- a/third_party/nix/test-vm.nix
+++ b/third_party/nix/test-vm.nix
@@ -1,10 +1,9 @@
 { depot, pkgs, ... }:
 
 let
-
   configuration = { ... }: {
     imports = [
-      "${pkgs.nixpkgsSrc}/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix"
+      "${pkgs.path}/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix"
     ];
 
     nix.package = depot.third_party.nix;
@@ -16,6 +15,5 @@ let
     ];
   };
 
-  system = pkgs.nixos { inherit configuration; };
-
+  system = depot.third_party.nixos { inherit configuration; };
 in system.vm
diff --git a/third_party/nixpkgs-exposed/.skip-subtree b/third_party/nixpkgs-exposed/.skip-subtree
deleted file mode 100644
index aff471145e..0000000000
--- a/third_party/nixpkgs-exposed/.skip-subtree
+++ /dev/null
@@ -1 +0,0 @@
-This subtree is responsible for setting up the read tree arguments in the first place.
diff --git a/third_party/nixpkgs-exposed/OWNERS b/third_party/nixpkgs-exposed/OWNERS
deleted file mode 100644
index 72c0ac47fb..0000000000
--- a/third_party/nixpkgs-exposed/OWNERS
+++ /dev/null
@@ -1,8 +0,0 @@
-# The nixpkgs whitelist needs to be changed every time we reference
-# a new attribute, so every commiter should be able to change it,
-# otherwise we create undue blockers on superowners.
-inherited: true
-owners:
-  - Profpatsch
-  - sterni
-  - glittershark
diff --git a/third_party/nixpkgs-exposed/exposed/default.nix b/third_party/nixpkgs-exposed/exposed/default.nix
deleted file mode 100644
index 478b55cb29..0000000000
--- a/third_party/nixpkgs-exposed/exposed/default.nix
+++ /dev/null
@@ -1,210 +0,0 @@
-# This file has to be in yet another subdir
-# because of how readTree interprets .skip-subtree
-# see https://b.tvl.fyi/issues/89
-{ nixpkgs, stableNixpkgs }:
-{
-  # Inherit the packages from nixos-unstable that should be available inside
-  # of the repo. They become available under `pkgs.third_party.<name>`
-  inherit (nixpkgs)
-    age
-    atk
-    autoconf
-    autoreconfHook
-    avrdude
-    avrlibc
-    bashInteractive
-    bat
-    bc
-    bind
-    buildBazelPackage
-    buildFHSUserEnv
-    buildGoModule
-    buildGoPackage
-    buildPackages
-    buildRustCrate
-    buildkite-agent
-    busybox
-    bzip2
-    c-ares
-    cacert
-    cachix
-    cairo
-    cargo
-    cgit
-    clang_11
-    cmake
-    coreutils
-    cudatoolkit
-    darwin
-    dbus-glib
-    dbus_libs
-    dfu-programmer
-    dfu-util
-    diffutils
-    docker-compose
-    dockerTools
-    emacs27
-    emacs27-nox
-    emacsPackages
-    emacsPackagesGen
-    execline
-    fd
-    fdtools
-    fetchFromGitHub
-    fetchFromGitLab
-    fetchgit
-    fetchurl
-    fetchzip
-    ffmpeg-full
-    findutils
-    fira
-    fira-code
-    fira-mono
-    flamegraph
-    fontconfig
-    freetype
-    gdk-pixbuf
-    gettext
-    glibc
-    glib
-    gtk3
-    gmock
-    gnused
-    gnutar
-    go
-    google-cloud-sdk
-    graphviz
-    gzip
-    haskell
-    iana-etc
-    imagemagickBig
-    installShellFiles
-    jdk
-    jdk11
-    jdk11_headless
-    jetbrains-mono
-    jq
-    kontemplate
-    lib
-    libappindicator-gtk3
-    libredirect
-    libffi
-    linuxPackages
-    linuxPackages_5_11
-    lr
-    luajit
-    lutris
-    makeFontsConf
-    makeWrapper
-    mandoc
-    mdbook
-    meson
-    mime-types
-    minify
-    mkShell
-    moreutils
-    nano
-    ncurses
-    nginx
-    ninja
-    nix
-    ocamlPackages
-    openssh
-    openssl
-    overrideCC
-    pandoc
-    pango
-    parallel
-    path
-    pkgconfig
-    pkgsCross
-    plantuml
-    postgresql
-    pounce
-    pulseaudio
-    python3
-    python3Packages
-    quassel
-    remarshal
-    rink
-    ripgrep
-    rsync
-    runCommand
-    runCommandLocal
-    runCommandNoCC
-    rustPlatform
-    rustc
-    s6-portable-utils
-    sbcl
-    shellcheck
-    sqlite
-    stdenvNoCC
-    stern
-    substituteAll
-    symlinkJoin
-    systemd
-    tdlib
-    teensy-loader-cli
-    terraform_0_12
-    texlive
-    thttpd
-    tree
-    tree-sitter
-    unzip
-    which
-    writers
-    writeShellScript
-    writeShellScriptBin
-    writeText
-    xorg
-    xz
-    zlib
-    zstd;
-
-  # Inherit packages from the stable channel for things that are
-  # broken on unstable
-  inherit (stableNixpkgs)
-    awscli # TODO(grfn): Move back to unstable once it is fixed
-    ;
-
-  # Required by //third_party/nix
-  inherit (nixpkgs)
-    aws-sdk-cpp
-    bison
-    boehmgc
-    boost # urgh
-    brotli
-    busybox-sandbox-shell
-    curl
-    docbook5
-    docbook_xsl_ns
-    editline
-    flex
-    libseccomp
-    libsodium
-    libxml2
-    libxslt
-    mercurial
-    perl
-    perlPackages
-    ;
-
-  haskellPackages = (nixpkgs.haskellPackages.override {
-    overrides = (import ../../overlays/haskell
-    { /* empty readTree arg */ }
-    { pkgs = nixpkgs; });
-  });
-
-  gradle_6 = (nixpkgs.gradleGen.override {
-    java = nixpkgs.jdk11;
-    jdk = nixpkgs.jdk11;
-  }).gradleGen rec {
-    name = "gradle-6.5.1";
-    nativeVersion = "0.22-milestone-3";
-
-    src = builtins.fetchurl {
-      url = "https://services.gradle.org/distributions/${name}-bin.zip";
-      sha256 = "0jmmipjh4fbsn92zpifa5cqg5ws2a4ha0s4jzqhrg4zs542x79sh";
-    };
-  };
-}
diff --git a/third_party/nixpkgs/default.nix b/third_party/nixpkgs/default.nix
new file mode 100644
index 0000000000..53adfe81e3
--- /dev/null
+++ b/third_party/nixpkgs/default.nix
@@ -0,0 +1,56 @@
+# This file imports the pinned nixpkgs sets and applies relevant
+# modifications, such as our overlays.
+#
+# Note that the attribute exposed by this (third_party.nixpkgs) is
+# "special" in that the fixpoint used as readTree's config parameter
+# in //default.nix passes this attribute as the `pkgs` argument to all
+# readTree derivations.
+
+{ depot, ... }:
+
+let
+  # This provides the sources of nixpkgs. We track both
+  # nixos-unstable, and the current stable channel of the latest NixOS
+  # release.
+
+  # Tracking nixos-unstable as of 2021-03-25.
+  unstableHashes = {
+    commit = "60dd94fb7e01a8288f6638eee71d7cb354c49327";
+    sha256 = "0skdwk9bdld295kzrymirs8xrzycqmhsclaz8s18jhcz75hb8sk3";
+  };
+
+  # Tracking nixos-20.09 as of 2021-03-25.
+  stableHashes = {
+    commit = "223d0d733a66b46504ea6b4c15f88b7cc4db58fb";
+    sha256 = "073327ris0frqa3kpid3nsjr9w8yx2z83xpsc24w898mrs9r7d5v";
+  };
+
+  nixpkgsSrc = fetchTarball {
+    url = "https://github.com/NixOS/nixpkgs/archive/${unstableHashes.commit}.tar.gz";
+    sha256 = unstableHashes.sha256;
+  };
+  stableNixpkgsSrc = fetchTarball {
+    url = "https://github.com/NixOS/nixpkgs/archive/${stableHashes.commit}.tar.gz";
+    sha256 = stableHashes.sha256;
+  };
+
+  # Stable package set is imported, but not exposed, to overlay
+  # required packages into the unstable set.
+  stableNixpkgs = import stableNixpkgsSrc {};
+
+  # Overlay for packages that should come from the stable channel
+  # instead (e.g. because something is broken in unstable).
+  stableOverlay = self: super: {
+    inherit (stableNixpkgs)
+      awscli # TODO(grfn): Move back to unstable once it is fixed
+      ;
+  };
+in import nixpkgsSrc {
+  config.allowUnfree = true;
+  config.allowBroken = true;
+  overlays = [
+    stableOverlay
+    depot.third_party.overlays.tvl
+    depot.third_party.overlays.haskell
+  ];
+}
diff --git a/third_party/notmuch/default.nix b/third_party/notmuch/default.nix
index 8e1e9c2626..9066083726 100644
--- a/third_party/notmuch/default.nix
+++ b/third_party/notmuch/default.nix
@@ -1,6 +1,7 @@
+# Notmuch, but with support for https://dotti.me/
 { pkgs, ... }:
 
-pkgs.originals.notmuch.overrideAttrs(old: {
+pkgs.notmuch.overrideAttrs(old: {
   doCheck = false;
   patches = [ ./dottime.patch ] ++ (if old ? patches then old.patches else []);
 })
diff --git a/third_party/openldap/default.nix b/third_party/openldap/default.nix
index 92de8d3fea..aed051c4e0 100644
--- a/third_party/openldap/default.nix
+++ b/third_party/openldap/default.nix
@@ -6,7 +6,7 @@
 # derivation to include this module.
 { pkgs, ... }:
 
-pkgs.originals.openldap.overrideAttrs(old: {
+pkgs.openldap.overrideAttrs(old: {
   buildInputs = old.buildInputs ++ [ pkgs.libsodium ];
 
   postBuild = ''
diff --git a/third_party/overlays/haskell/default.nix b/third_party/overlays/haskell/default.nix
index 975918803e..7b17e61e3e 100644
--- a/third_party/overlays/haskell/default.nix
+++ b/third_party/overlays/haskell/default.nix
@@ -1,34 +1,41 @@
-# Defines overrides for Haskell packages, for example to avoid
-# breakage currently present in nixpkgs or to modify package versions.
+# Defines an overlay for overriding Haskell packages, for example to
+# avoid breakage currently present in nixpkgs or to modify package
+# versions.
 
 { ... }: # This file needs nothing from readTree
-{ pkgs }: # ... but is called with a separate package set in the overlay
 
-self: super: with pkgs.haskell.lib; rec {
-  generic-arbitrary = appendPatch
-    super.generic-arbitrary
-    [ ./patches/generic-arbitrary-export-garbitrary.patch ];
+self: super: # overlay parameters for the nixpkgs overlay
 
-  random = dontCheck (self.callHackageDirect {
-    pkg = "random";
-    ver = "1.2.0";
-    sha256 = "06s3mmqbsfwv09j2s45qnd66nrxfp9280gnl9ng8yh128pfr7bjh";
-  } {});
+let
+  overrides = hsSelf: hsSuper: with super.haskell.lib; rec {
+    generic-arbitrary = appendPatch hsSuper.generic-arbitrary
+      [ ./patches/generic-arbitrary-export-garbitrary.patch ];
 
-  # random <1.2
-  test-framework = doJailbreak super.test-framework;
-  hashable = doJailbreak super.hashable;
-  test-framework-quickcheck2 = doJailbreak super.test-framework-quickcheck2;
+    # random = dontCheck (hsSuper.callHackageDirect {
+    #   pkg = "random";
+    #   ver = "1.2.0";
+    #   sha256 = "06s3mmqbsfwv09j2s45qnd66nrxfp9280gnl9ng8yh128pfr7bjh";
+    # } {});
 
-  # can be removed if we have the following PR or equivalent
-  # https://github.com/NixOS/nixpkgs/pull/116931
-  hedgehog-classes = overrideCabal super.hedgehog-classes (attrs: {
-    # remove version bound on semirings which is inside a
-    # conditional, so doJailbreak doesn't work
-    prePatch = ''
-      sed -i 's|semirings.*0.6|semirings|g' hedgehog-classes.cabal
-    '';
-  });
+    # random <1.2
+    test-framework = doJailbreak hsSuper.test-framework;
+    hashable = doJailbreak hsSuper.hashable;
+    test-framework-quickcheck2 = doJailbreak hsSuper.test-framework-quickcheck2;
 
-  hgeometry-combinatorial = dontCheck super.hgeometry-combinatorial;
+    # can be removed if we have the following PR or equivalent
+    # https://github.com/NixOS/nixpkgs/pull/116931
+    hedgehog-classes = overrideCabal hsSuper.hedgehog-classes (attrs: {
+      # remove version bound on semirings which is inside a
+      # conditional, so doJailbreak doesn't work
+      prePatch = ''
+        sed -i 's|semirings.*0.6|semirings|g' hedgehog-classes.cabal
+      '';
+    });
+
+    hgeometry-combinatorial = dontCheck hsSuper.hgeometry-combinatorial;
+  };
+in {
+  haskellPackages = super.haskellPackages.override {
+    inherit overrides;
+  };
 }
diff --git a/third_party/overlays/tvl.nix b/third_party/overlays/tvl.nix
new file mode 100644
index 0000000000..01f7156ff1
--- /dev/null
+++ b/third_party/overlays/tvl.nix
@@ -0,0 +1,27 @@
+# This overlay is used to make TVL-specific modifications in the
+# nixpkgs tree, where required.
+{ ... }:
+
+self: super: {
+  # Required for apereo-cas
+  # TODO(lukegb): Document why?
+  gradle_6 = (super.gradleGen.override {
+    java = self.jdk11;
+    jdk = self.jdk11;
+  }).gradleGen rec {
+    name = "gradle-6.5.1";
+    nativeVersion = "0.22-milestone-3";
+
+    src = builtins.fetchurl {
+      url = "https://services.gradle.org/distributions/${name}-bin.zip";
+      sha256 = "0jmmipjh4fbsn92zpifa5cqg5ws2a4ha0s4jzqhrg4zs542x79sh";
+    };
+  };
+
+  # Use LLVM 11
+  llvmPackages = self.llvmPackages_11;
+  clangStdenv = self.llvmPackages_11.stdenv;
+  clang-tools = (super.clang-tools.override {
+    llvmPackages = self.llvmPackages_11;
+  });
+}
diff --git a/third_party/protobuf/default.nix b/third_party/protobuf/default.nix
index ce4a2f8aa5..c9e34b2fc3 100644
--- a/third_party/protobuf/default.nix
+++ b/third_party/protobuf/default.nix
@@ -1,7 +1,7 @@
 # Pin protobuf to version 3.12, with LLVM.
 { depot, pkgs, ... }:
 
-pkgs.callPackage "${depot.third_party.nixpkgsSrc}/pkgs/development/libraries/protobuf/generic-v3.nix" {
+pkgs.callPackage "${pkgs.path}/pkgs/development/libraries/protobuf/generic-v3.nix" {
   version = "3.12.2";
   sha256 = "1lp368aa206vpic9fmax4k6llnmf28plfvkkm4vqhgphmjqykvl2";
   stdenv = pkgs.llvmPackages.libcxxStdenv;
diff --git a/third_party/rr/default.nix b/third_party/rr/default.nix
deleted file mode 100644
index 8f2cf85cc5..0000000000
--- a/third_party/rr/default.nix
+++ /dev/null
@@ -1,16 +0,0 @@
-{ pkgs, ... }:
-
-pkgs.originals.rr.overrideAttrs(_: {
-  src = pkgs.fetchFromGitHub {
-    owner = "mozilla";
-    repo = "rr";
-    rev = "8fc7d2a09a739fee1883d262501e88613165c1dd";
-    sha256 = "0avq5lv082z2sasggfn2awnfrh08cr8f0i9iw1dnrcxa6pc3bi9k";
-    fetchSubmodules = false;
-  };
-
-  # Workaround as documented on https://github.com/mozilla/rr/wiki/Zen
-  postInstall = ''
-    cp $src/scripts/zen_workaround.py $out/bin/rr_zen_workaround
-  '';
-})
diff --git a/users/Profpatsch/writers/tests/default.nix b/users/Profpatsch/writers/tests/default.nix
index 4b28792f75..e61bf482ee 100644
--- a/users/Profpatsch/writers/tests/default.nix
+++ b/users/Profpatsch/writers/tests/default.nix
@@ -1,4 +1,4 @@
-{ depot, ... }:
+{ depot, pkgs, ... }:
 
 let
   inherit (depot.users.Profpatsch.writers)
@@ -9,7 +9,7 @@ let
     rustSimpleBin
     ;
 
-  inherit (depot.third_party)
+  inherit (pkgs)
     coreutils
     ;
 
diff --git a/users/glittershark/achilles/default.nix b/users/glittershark/achilles/default.nix
index 8ce6fda5c1..4ad71455d4 100644
--- a/users/glittershark/achilles/default.nix
+++ b/users/glittershark/achilles/default.nix
@@ -1,6 +1,6 @@
-{ pkgs, ... }:
+{ depot, pkgs, ... }:
 
-pkgs.naersk.buildPackage {
+depot.third_party.naersk.buildPackage {
   src = ./.;
 
   buildInputs = with pkgs; [
diff --git a/users/glittershark/owothia/default.nix b/users/glittershark/owothia/default.nix
index 171bb36689..e10098ed94 100644
--- a/users/glittershark/owothia/default.nix
+++ b/users/glittershark/owothia/default.nix
@@ -1,4 +1,6 @@
-{ pkgs ? (import ../../../. {}).third_party, ... }:
+{ depot ? (import ../../../. {})
+, pkgs ? depot.third_party.nixpkgs
+, ... }:
 
 pkgs.haskellPackages.callCabal2nix "owothia"
-  (pkgs.gitignoreSource ./.) { }
+  (depot.third_party.gitignoreSource ./.) { }
diff --git a/users/glittershark/pkgs/fprintd/default.nix b/users/glittershark/pkgs/fprintd/default.nix
index 0f9d414aeb..1a977e34d3 100644
--- a/users/glittershark/pkgs/fprintd/default.nix
+++ b/users/glittershark/pkgs/fprintd/default.nix
@@ -1,9 +1,11 @@
-args @ { pkgs, ... }:
+{ depot, pkgs, ... }:
 
 let
-  nixpkgs = import pkgs.nixpkgsSrc {
+  nixpkgs = import pkgs.path {
     config.allowUnfree = true;
     overlays = [(self: super: {
+      # TODO(grfn): Can we not override this here? It bootstraps
+      # rustc, builds firefox, and many other things.
       gcc = super.gcc9;
     })];
   };
diff --git a/users/glittershark/system/home/default.nix b/users/glittershark/system/home/default.nix
index 1d6d8795ab..1efba3f3c1 100644
--- a/users/glittershark/system/home/default.nix
+++ b/users/glittershark/system/home/default.nix
@@ -3,15 +3,13 @@
 with lib;
 
 rec {
-  nixpkgs = import pkgs.nixpkgsSrc {};
-
-  home = confPath: (import "${nixpkgs.home-manager.src}/modules" {
-    pkgs = nixpkgs;
+  home = confPath: (import "${pkgs.home-manager.src}/modules" {
+    inherit pkgs;
     configuration = { config, lib, ... }: {
       imports = [confPath];
 
       _module.args.pkgs = mkForce
-        (import pkgs.nixpkgsSrc (filterAttrs (n: v: v != null) config.nixpkgs));
+        (import pkgs.path (filterAttrs (n: v: v != null) config.nixpkgs));
 
       lib.depot = depot;
     };
diff --git a/users/glittershark/system/home/modules/development.nix b/users/glittershark/system/home/modules/development.nix
index 1152a3395a..04a501e74b 100644
--- a/users/glittershark/system/home/modules/development.nix
+++ b/users/glittershark/system/home/modules/development.nix
@@ -54,7 +54,7 @@ with lib;
     gdb
     lldb
     hyperfine
-    config.lib.depot.third_party.clang-tools
+    clang-tools
 
     clj2nix
     clojure
diff --git a/users/glittershark/system/system/default.nix b/users/glittershark/system/system/default.nix
index a640b3337c..78cab61a01 100644
--- a/users/glittershark/system/system/default.nix
+++ b/users/glittershark/system/system/default.nix
@@ -1,19 +1,15 @@
 args @ { depot, pkgs, ... }:
 
-let
-  nixpkgs = import pkgs.nixpkgsSrc {};
-in
-
 rec {
   chupacabra = import ./machines/chupacabra.nix;
 
-  chupacabraSystem = (pkgs.nixos {
+  chupacabraSystem = (depot.third_party.nixos {
     configuration = chupacabra;
   }).system;
 
   mugwump = import ./machines/mugwump.nix;
 
-  mugwumpSystem = (pkgs.nixos {
+  mugwumpSystem = (depot.third_party.nixos {
     configuration = mugwump;
   }).system;
 
@@ -22,14 +18,14 @@ rec {
   roswellSystem = (depot.ops.nixos.nixosFor ({ ... }: {
     imports = [
       ./machines/roswell.nix
-      "${nixpkgs.home-manager.src}/nixos"
+      "${pkgs.home-manager.src}/nixos"
     ];
 
     home-manager.users.grfn = { config, lib, ... }: {
       imports = [ ../home/machines/roswell.nix ];
       lib.depot = depot;
       _module.args.pkgs = lib.mkForce
-        (import pkgs.nixpkgsSrc
+        (import pkgs.path
           (lib.filterAttrs (n: v: v != null) config.nixpkgs));
     };
   })).system;
@@ -60,7 +56,7 @@ rec {
           system=$(nix-build -E '(import ${depotPath} {}).users.glittershark.system.system.${hostname}' --no-out-link)
           ;;
       '';
-    in depot.third_party.writeShellScriptBin "rebuilder" ''
+    in pkgs.writeShellScriptBin "rebuilder" ''
       set -ue
       if [[ $EUID -ne 0 ]]; then
         echo "Oh no! Only root is allowed to rebuild the system!" >&2
diff --git a/users/glittershark/system/system/iso.nix b/users/glittershark/system/system/iso.nix
index 056922ee1e..256aee6a5e 100644
--- a/users/glittershark/system/system/iso.nix
+++ b/users/glittershark/system/system/iso.nix
@@ -1,17 +1,17 @@
-{ pkgs, ... }:
+{ depot, lib, pkgs, ... }:
 
 let
   configuration = { ... }: {
     imports = [
-      "${pkgs.nixpkgsSrc}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel.nix"
-      "${pkgs.nixpkgsSrc}/nixos/modules/installer/cd-dvd/channel.nix"
+      "${pkgs.path}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel.nix"
+      "${pkgs.path}/nixos/modules/installer/cd-dvd/channel.nix"
     ];
 
     networking.networkmanager.enable = true;
     networking.useDHCP = false;
     networking.firewall.enable = false;
-    networking.wireless.enable = pkgs.lib.mkForce false;
+    networking.wireless.enable = lib.mkForce false;
   };
-in (pkgs.nixos {
+in (depot.third_party.nixos {
   inherit configuration;
 }).config.system.build.isoImage
diff --git a/users/glittershark/xanthous/default.nix b/users/glittershark/xanthous/default.nix
index 0b89a50afb..c417c7af3e 100644
--- a/users/glittershark/xanthous/default.nix
+++ b/users/glittershark/xanthous/default.nix
@@ -4,4 +4,6 @@
 }:
 pkgs.haskell.lib.failOnAllWarnings (
   pkgs.haskellPackages.callPackage (import ./pkg.nix { inherit pkgs; }) {}
-)
+) // {
+  meta.ci = false;
+}
diff --git a/users/glittershark/xanthous/pkg.nix b/users/glittershark/xanthous/pkg.nix
index 98a9b9b6a6..16a6500866 100644
--- a/users/glittershark/xanthous/pkg.nix
+++ b/users/glittershark/xanthous/pkg.nix
@@ -1,10 +1,10 @@
-{ pkgs ? (import ../../../. {}).third_party }:
+{ depot ? (import ../../../. {})
+, pkgs ? depot.third_party.nixpkgs
+, ... }:
 
 let
-  ignore = pkgs.gitignoreSource.gitignoreFilter ./.;
-in
-
-import (pkgs.haskellPackages.haskellSrc2nix {
+  ignore = depot.third_party.gitignoreSource.gitignoreFilter ./.;
+in import (pkgs.haskellPackages.haskellSrc2nix {
   name = "xanthous";
   src = builtins.path {
     name = "xanthous-source";
diff --git a/users/tazjin/aoc2020/default.nix b/users/tazjin/aoc2020/default.nix
index 5989224f8d..7a7309ac5a 100644
--- a/users/tazjin/aoc2020/default.nix
+++ b/users/tazjin/aoc2020/default.nix
@@ -1,7 +1,7 @@
 # Solutions for Advent of Code 2020, written in Emacs Lisp.
 #
 # For each day a new file is created as "solution-day$n.el".
-{ depot, ... }:
+{ depot, pkgs, ... }:
 
 let
   inherit (builtins) attrNames filter head listToAttrs match readDir;
@@ -16,7 +16,7 @@ let
       deps = p: with p; [ dash s ht p.f ];
       src = ./. + ("/" + f);
   }) solutionFiles;
-in depot.third_party.symlinkJoin {
+in pkgs.symlinkJoin {
   name = "aoc2020";
   paths = solutions;
 }
diff --git a/users/tazjin/atom-feed/default.nix b/users/tazjin/atom-feed/default.nix
index fe5e4b997c..9ed2c61892 100644
--- a/users/tazjin/atom-feed/default.nix
+++ b/users/tazjin/atom-feed/default.nix
@@ -1,13 +1,13 @@
 # This file defines functions for generating an Atom feed.
 
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 with depot.nix.yants;
 
 let
   inherit (builtins) map readFile replaceStrings;
   inherit (lib) concatStrings concatStringsSep removeSuffix;
-  inherit (depot.third_party) runCommandNoCC;
+  inherit (pkgs) runCommandNoCC;
 
   # 'link' describes a related link to a feed, or feed element.
   #
diff --git a/users/tazjin/blog/default.nix b/users/tazjin/blog/default.nix
index a5254b5496..a3c373a0fa 100644
--- a/users/tazjin/blog/default.nix
+++ b/users/tazjin/blog/default.nix
@@ -2,7 +2,7 @@
 # files in this repository.
 #
 # All blog posts are rendered from Markdown by cheddar.
-{ depot, lib, ... }@args:
+{ depot, lib, pkgs, ... }@args:
 
 with depot.nix.yants;
 
@@ -36,7 +36,7 @@ let
   posts = list post (import ./posts.nix);
   fragments = import ./fragments.nix args;
 
-  rendered = depot.third_party.runCommandNoCC "tazjins-blog" {} ''
+  rendered = pkgs.runCommandNoCC "tazjins-blog" {} ''
     mkdir -p $out
 
     ${lib.concatStringsSep "\n" (map (post:
diff --git a/users/tazjin/blog/fragments.nix b/users/tazjin/blog/fragments.nix
index 98028fad70..1ffddeeb67 100644
--- a/users/tazjin/blog/fragments.nix
+++ b/users/tazjin/blog/fragments.nix
@@ -7,11 +7,11 @@
 #
 # The post index is generated by //users/tazjin/homepage, not by this
 # code.
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 let
   inherit (builtins) filter map hasAttr replaceStrings;
-  inherit (depot.third_party) runCommandNoCC writeText;
+  inherit (pkgs) runCommandNoCC writeText;
   inherit (depot.users.tazjin) renderMarkdown;
 
   # Generate a post list for all listed, non-draft posts.
diff --git a/users/tazjin/dt/default.nix b/users/tazjin/dt/default.nix
index 04430c883b..8a728062db 100644
--- a/users/tazjin/dt/default.nix
+++ b/users/tazjin/dt/default.nix
@@ -1,13 +1,11 @@
 { depot, pkgs, ... }:
 
-let
-  stdenv = with pkgs; overrideCC clangStdenv clang_11;
-  abseil_cpp = pkgs.abseil_cpp;
+let stdenv = with pkgs; overrideCC clangStdenv clang_11;
 in stdenv.mkDerivation {
   name = "dt";
   src = ./.;
   nativeBuildInputs = [ pkgs.cmake ];
-  buildInputs = with pkgs; [
+  buildInputs = with depot.third_party; [
     abseil_cpp
     farmhash
   ];
diff --git a/users/tazjin/emacs/default.nix b/users/tazjin/emacs/default.nix
index c7f0f8c03d..b4d5f952e9 100644
--- a/users/tazjin/emacs/default.nix
+++ b/users/tazjin/emacs/default.nix
@@ -10,12 +10,10 @@
 { depot, lib, pkgs, ... }:
 
 let
-  inherit (depot) third_party;
-
-  emacsWithPackages = (third_party.emacsPackagesGen third_party.emacs27).emacsWithPackages;
+  emacsWithPackages = (pkgs.emacsPackagesGen pkgs.emacs27).emacsWithPackages;
 
   # $PATH for binaries that need to be available to Emacs
-  emacsBinPath = lib.makeBinPath [ third_party.emacsPackages.telega ];
+  emacsBinPath = lib.makeBinPath [ pkgs.emacsPackages.telega ];
 
   identity = x: x;
 
@@ -109,7 +107,7 @@ let
     depot.third_party.emacs.vterm
     depot.third_party.emacs.explain-pause-mode
   ]))));
-in lib.fix(self: l: f: third_party.writeShellScriptBin "tazjins-emacs" ''
+in lib.fix(self: l: f: pkgs.writeShellScriptBin "tazjins-emacs" ''
   export PATH="${emacsBinPath}:$PATH"
   exec ${tazjinsEmacs f}/bin/emacs \
     --debug-init \
@@ -129,7 +127,7 @@ in lib.fix(self: l: f: third_party.writeShellScriptBin "tazjins-emacs" ''
 
     # Build a derivation that uses the specified local Emacs (i.e.
     # built outside of Nix) instead
-    withLocalEmacs = emacsBin: third_party.writeShellScriptBin "tazjins-emacs" ''
+    withLocalEmacs = emacsBin: pkgs.writeShellScriptBin "tazjins-emacs" ''
       export PATH="${emacsBinPath}:$PATH"
       export EMACSLOADPATH="${(tazjinsEmacs f).deps}/share/emacs/site-lisp:"
       exec ${emacsBin} \
diff --git a/users/tazjin/homepage/default.nix b/users/tazjin/homepage/default.nix
index 8f53eba67e..17d5d5cc87 100644
--- a/users/tazjin/homepage/default.nix
+++ b/users/tazjin/homepage/default.nix
@@ -5,14 +5,14 @@
 # elements for things such as blog posts and projects.
 #
 # Content for the blog is in //users/tazjin/blog instead of here.
-{ depot, lib, ... }@args:
+{ depot, lib, pkgs, ... }@args:
 
 with depot;
 with nix.yants;
 
 let
   inherit (builtins) readFile replaceStrings sort;
-  inherit (third_party) writeFile runCommandNoCC;
+  inherit (pkgs) writeFile runCommandNoCC;
 
   # The different types of entries on the homepage.
   entryClass = enum "entryClass" [ "blog" "project" "misc" ];
@@ -58,7 +58,7 @@ let
     </a>
   '');
 
-  index = entries: third_party.writeText "index.html" (lib.concatStrings (
+  index = entries: pkgs.writeText "index.html" (lib.concatStrings (
     [ (builtins.readFile ./header.html) ]
     ++ (map entryToDiv (sort (a: b: a.date > b.date) entries))
     ++ [ (builtins.readFile ./footer.html) ]
diff --git a/users/tazjin/nixos/camden/default.nix b/users/tazjin/nixos/camden/default.nix
index d5a9d61bda..f334320b38 100644
--- a/users/tazjin/nixos/camden/default.nix
+++ b/users/tazjin/nixos/camden/default.nix
@@ -2,7 +2,7 @@
 { depot, pkgs, lib, ... }:
 
 config: let
-  nixpkgs = import depot.third_party.nixpkgsSrc {
+  nixpkgs = import pkgs.path {
     config.allowUnfree = true;
   };
 
@@ -85,7 +85,7 @@ in lib.fix(self: {
 
     nixPath = [
       "depot=/home/tazjin/depot"
-      "nixpkgs=${depot.third_party.nixpkgsSrc}"
+      "nixpkgs=${pkgs.path}"
     ];
 
     trustedUsers = [ "root" "tazjin" ];
@@ -131,7 +131,6 @@ in lib.fix(self: {
     (with depot; [
       fun.idual.script
       fun.idual.setAlarm
-      third_party.pounce
     ]) ++
 
     # programs from nixpkgs
diff --git a/users/tazjin/nixos/frog/default.nix b/users/tazjin/nixos/frog/default.nix
index dcc955f968..35d58147d4 100644
--- a/users/tazjin/nixos/frog/default.nix
+++ b/users/tazjin/nixos/frog/default.nix
@@ -1,23 +1,20 @@
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 config: let
   inherit (depot.third_party) lieer;
-  nixpkgs = import depot.third_party.nixpkgsSrc {
-    config.allowUnfree = true;
-  };
 
   # add google-c-style here because other machines get it from, eh,
   # elsewhere.
   frogEmacs = (depot.users.tazjin.emacs.overrideEmacs(epkgs: epkgs ++ [
-    depot.third_party.emacsPackages.google-c-style
+    pkgs.emacsPackages.google-c-style
   ]));
 
-  quasselClient = depot.third_party.quassel.override {
+  quasselClient = pkgs.quassel.override {
     client = true;
     enableDaemon = false;
     monolithic = false;
   };
-in depot.lib.fix(self: {
+in lib.fix(self: {
   imports = [
     "${depot.depotPath}/ops/nixos/v4l2loopback.nix"
   ];
@@ -37,7 +34,7 @@ in depot.lib.fix(self: {
       kernelModules = [ "dm-snapshot" ];
     };
 
-    kernelPackages = nixpkgs.linuxPackages_latest;
+    kernelPackages = pkgs.linuxPackages_latest;
     kernel.sysctl = {
       "kernel.perf_event_paranoid" = -1;
     };
@@ -58,7 +55,7 @@ in depot.lib.fix(self: {
 
     pulseaudio = {
       enable = true;
-      package = nixpkgs.pulseaudioFull;
+      package = pkgs.pulseaudioFull;
     };
 
     bluetooth = {
@@ -70,14 +67,14 @@ in depot.lib.fix(self: {
     maxJobs = 48;
     nixPath = [
       "depot=/depot"
-      "nixpkgs=${depot.third_party.nixpkgsSrc}"
+      "nixpkgs=${pkgs.path}"
     ];
 
     binaryCaches = ["ssh://nix-ssh@whitby.tvl.fyi"];
     binaryCachePublicKeys = ["cache.tvl.fyi:fd+9d1ceCPvDX/xVhcfv8nAa6njEhAGAEe+oGJDEeoc="];
   };
 
-  nixpkgs.pkgs = nixpkgs;
+  nixpkgs.pkgs = pkgs;
 
   networking = {
     hostName = "frog";
@@ -95,7 +92,7 @@ in depot.lib.fix(self: {
   # Generate an immutable /etc/resolv.conf from the nameserver settings
   # above (otherwise DHCP overwrites it):
   environment.etc."resolv.conf" = with lib; {
-    source = depot.third_party.writeText "resolv.conf" ''
+    source = pkgs.writeText "resolv.conf" ''
       ${concatStringsSep "\n" (map (ns: "nameserver ${ns}") self.networking.nameservers)}
       options edns0
     '';
@@ -114,7 +111,7 @@ in depot.lib.fix(self: {
     extraGroups = [ "wheel" "audio" "docker" ];
     isNormalUser = true;
     uid = 1000;
-    shell = nixpkgs.fish;
+    shell = pkgs.fish;
   };
 
   security.sudo = {
@@ -123,7 +120,7 @@ in depot.lib.fix(self: {
   };
 
   fonts = {
-    fonts = with nixpkgs; [
+    fonts = with pkgs; [
       corefonts
       dejavu_fonts
       jetbrains-mono
@@ -158,7 +155,7 @@ in depot.lib.fix(self: {
   # Required for Yubikey usage as smartcard
   services.pcscd.enable = true;
   services.udev.packages = [
-    nixpkgs.yubikey-personalization
+    pkgs.yubikey-personalization
   ];
 
   # Enable Docker for Nixery testing
@@ -175,7 +172,7 @@ in depot.lib.fix(self: {
     videoDrivers = [ "amdgpu" ];
     displayManager = {
       # Give EXWM permission to control the session.
-      sessionCommands = "${nixpkgs.xorg.xhost}/bin/xhost +SI:localuser:$USER";
+      sessionCommands = "${pkgs.xorg.xhost}/bin/xhost +SI:localuser:$USER";
 
       lightdm.enable = true;
       lightdm.greeters.gtk.clock-format = "%H·%M"; # TODO(tazjin): TZ?
@@ -224,15 +221,12 @@ in depot.lib.fix(self: {
       lieer
       ops.kontemplate
       quasselClient
-      third_party.ffmpeg
       third_party.git
-      third_party.lutris
-      third_party.rr
       tools.nsfv-setup
     ]) ++
 
     # programs from nixpkgs
-    (with nixpkgs; [
+    (with pkgs; [
       age
       bat
       chromium
@@ -245,6 +239,7 @@ in depot.lib.fix(self: {
       emacs27 # mostly for emacsclient
       exa
       fd
+      ffmpeg-full
       file
       gdb
       gnupg
@@ -259,6 +254,7 @@ in depot.lib.fix(self: {
       jq
       kubectl
       linuxPackages.perf
+      # lutris
       manpages
       miller
       msmtp
@@ -276,6 +272,7 @@ in depot.lib.fix(self: {
       pmutils
       pwgen
       ripgrep
+      rr
       rustup
       screen
       scrot
diff --git a/users/tazjin/nixos/tverskoy/default.nix b/users/tazjin/nixos/tverskoy/default.nix
index 42fd01c30e..c2694bf5eb 100644
--- a/users/tazjin/nixos/tverskoy/default.nix
+++ b/users/tazjin/nixos/tverskoy/default.nix
@@ -1,17 +1,17 @@
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 config: let
   # add google-c-style here because other machines get it from, eh,
   # elsewhere.
   emacs = (depot.users.tazjin.emacs.overrideEmacs(epkgs: epkgs ++ [
-    depot.third_party.emacsPackages.google-c-style
+    pkgs.emacsPackages.google-c-style
   ]));
 
-  nixpkgs = import depot.third_party.nixpkgsSrc {
+  nixpkgs = import pkgs.path {
     config.allowUnfree = true;
   };
 
-  quasselClient = depot.third_party.quassel.override {
+  quasselClient = pkgs.quassel.override {
     client = true;
     enableDaemon = false;
     monolithic = false;
@@ -33,8 +33,8 @@ in lib.fix(self: {
 
   nix = {
     nixPath = lib.mkForce [
-      "nixpkgs=${depot.third_party.nixpkgsSrc}"
-      "nixos=${depot.third_party.nixpkgsSrc}"
+      "nixpkgs=${pkgs.path}"
+      "nixos=${pkgs.path}"
       "depot=/depot"
     ];
 
diff --git a/users/tazjin/renderMarkdown.nix b/users/tazjin/renderMarkdown.nix
index 58f29c30e0..0994661cbb 100644
--- a/users/tazjin/renderMarkdown.nix
+++ b/users/tazjin/renderMarkdown.nix
@@ -1,9 +1,9 @@
 # Render a Markdown file to HTML.
-{ depot, ... }:
+{ depot, pkgs, ... }:
 
 with depot.nix.yants;
 
-defun [ path drv ] (file: depot.third_party.runCommandNoCC "${file}.rendered.html" {} ''
+defun [ path drv ] (file: pkgs.runCommandNoCC "${file}.rendered.html" {} ''
   cat ${file} | ${depot.tools.cheddar}/bin/cheddar --about-filter ${file} > $out
 '')
 
diff --git a/users/tazjin/rlox/default.nix b/users/tazjin/rlox/default.nix
index 4b2d650cb5..e50ac32be4 100644
--- a/users/tazjin/rlox/default.nix
+++ b/users/tazjin/rlox/default.nix
@@ -1,5 +1,5 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
-pkgs.naersk.buildPackage {
+depot.third_party.naersk.buildPackage {
   src = ./.;
 }
diff --git a/web/cgit-taz/default.nix b/web/cgit-taz/default.nix
index 636695c883..f2f47e5793 100644
--- a/web/cgit-taz/default.nix
+++ b/web/cgit-taz/default.nix
@@ -1,11 +1,15 @@
 # This derivation configures a 'cgit' instance to serve repositories
 # from a different source.
-
-{ depot, ... }:
-
-with depot.third_party;
+{ depot, pkgs, ... }:
 
 let
+  inherit (pkgs)
+    mime-types
+    thttpd
+    writeShellScriptBin
+    writeText
+    ;
+
   sourceFilter = writeShellScriptBin "cheddar-about" ''
     exec ${depot.tools.cheddar}/bin/cheddar --about-filter $@
   '';
@@ -33,7 +37,7 @@ let
 
   thttpdConfig = writeText "thttpd.conf" ''
     port=2448
-    dir=${cgit}/cgit
+    dir=${depot.third_party.cgit}/cgit
     nochroot
     novhost
     cgipat=**.cgi
diff --git a/web/converse/default.nix b/web/converse/default.nix
index a750671196..cc2dab7f88 100644
--- a/web/converse/default.nix
+++ b/web/converse/default.nix
@@ -1,6 +1,6 @@
-{ pkgs, ... }:
+{ depot, pkgs, ... }:
 
-pkgs.naersk.buildPackage {
+depot.third_party.naersk.buildPackage {
   src = ./.;
   buildInputs = with pkgs; [ openssl postgresql.lib ];
   nativeBuildInputs = [ pkgs.pkgconfig ];
diff --git a/web/todolist/default.nix b/web/todolist/default.nix
index 47640c8741..c9efbc03f9 100644
--- a/web/todolist/default.nix
+++ b/web/todolist/default.nix
@@ -2,12 +2,12 @@
 #
 # Only TODOs that match the form 'TODO($username)' are considered, and
 # only for users that are known to us.
-{ depot, lib, ... }:
+{ depot, lib, pkgs, ... }:
 
 with depot.nix.yants;
 
 let
-  inherit (depot.third_party)
+  inherit (pkgs)
     jq
     ripgrep
     runCommandNoCC