hydra: remove multi-version support

This is a legacy of when a "stable" version of hydra existed, and this
probably won't be coming back.

This also removes some obsolete bits which have no effect on the
result of evaluation.

Unlike the original approach in #157072, we're moving the common
expression to "unstable.nix" instead. This allow putting everything in
one commit, satisfies git's rename detection, and remains bisectable.

Co-Authored-By: Bernardo Meurer <bernardo@meurer.org>
Co-Authored-By: Linus Heckemann <git@sphalerite.org>

3 files changed, 29 insertions, 34 deletions

diff --git a/pkgs/development/tools/misc/hydra/default.nix b/pkgs/development/tools/misc/hydra/default.nix
deleted file mode 100644
index 5289015d43b24..0000000000000
--- a/pkgs/development/tools/misc/hydra/default.nix
+++ /dev/null
@@ -1,26 +0,0 @@
-{ lib, fetchFromGitHub, callPackage, nixVersions, nixosTests, fetchpatch }:
-
-{
-  hydra-unstable = callPackage ./common.nix {
-    version = "2022-02-07";
-    src = fetchFromGitHub {
-      owner = "NixOS";
-      repo = "hydra";
-      rev = "517dce285a851efd732affc084c7083aed2e98cd";
-      sha256 = "sha256-abWhd/VLNse3Gz7gcVbFANJLAhHV4nbOKjhVDmq/Zmg=";
-    };
-    patches = [
-      ./eval.patch
-      ./missing-std-string.patch
-      (fetchpatch {
-        url = "https://github.com/NixOS/hydra/commit/5ae26aa7604f714dcc73edcb74fe71ddc8957f6c.patch";
-        sha256 = "sha256-wkbWo8SFbT3qwVxwkKQWpQT5Jgb1Bb51yiLTlFdDN/I=";
-      })
-    ];
-    nix = nixVersions.nix_2_6;
-
-    tests = {
-      basic = nixosTests.hydra.hydra-unstable;
-    };
-  };
-}
diff --git a/pkgs/development/tools/misc/hydra/common.nix b/pkgs/development/tools/misc/hydra/unstable.nix
index 2314f5f9f64fb..7d3521702a792 100644
--- a/pkgs/development/tools/misc/hydra/common.nix
+++ b/pkgs/development/tools/misc/hydra/unstable.nix
@@ -1,16 +1,20 @@
-{ stdenv, nix, perlPackages, buildEnv
+{ stdenv
+, lib
+, nix, perlPackages, buildEnv
 , makeWrapper, autoconf, automake, libtool, unzip, pkg-config, sqlite, libpqxx_6
 , top-git, mercurial, darcs, subversion, breezy, openssl, bzip2, libxslt
 , perl, postgresql, nukeReferences, git, boehmgc, nlohmann_json
 , docbook_xsl, openssh, gnused, coreutils, findutils, gzip, xz, gnutar
-, rpm, dpkg, cdrkit, pixz, lib, boost, autoreconfHook, src ? null, version ? null
-, migration ? false, patches ? []
-, tests ? {}, mdbook
+, rpm, dpkg, cdrkit, pixz, boost, autoreconfHook
+, mdbook
 , foreman
 , python3
 , libressl
 , cacert
 , glibcLocales
+, fetchFromGitHub
+, fetchpatch
+, nixosTests
 }:
 
 let
@@ -88,8 +92,14 @@ let
   };
 in stdenv.mkDerivation rec {
   pname = "hydra";
+  version = "2022-02-07";
 
-  inherit stdenv src version patches;
+  src = fetchFromGitHub {
+    owner = "NixOS";
+    repo = "hydra";
+    rev = "517dce285a851efd732affc084c7083aed2e98cd";
+    sha256 = "sha256-abWhd/VLNse3Gz7gcVbFANJLAhHV4nbOKjhVDmq/Zmg=";
+  };
 
   buildInputs =
     [ makeWrapper libtool unzip nukeReferences sqlite libpqxx_6
@@ -116,6 +126,15 @@ in stdenv.mkDerivation rec {
     libressl.nc
   ];
 
+  patches = [
+    ./eval.patch
+    ./missing-std-string.patch
+    (fetchpatch {
+      url = "https://github.com/NixOS/hydra/commit/5ae26aa7604f714dcc73edcb74fe71ddc8957f6c.patch";
+      sha256 = "sha256-wkbWo8SFbT3qwVxwkKQWpQT5Jgb1Bb51yiLTlFdDN/I=";
+    })
+  ];
+
   configureFlags = [ "--with-docbook-xsl=${docbook_xsl}/xml/xsl/docbook" ];
 
   NIX_CFLAGS_COMPILE = "-pthread";
@@ -152,7 +171,10 @@ in stdenv.mkDerivation rec {
 
   doCheck = true;
 
-  passthru = { inherit perlDeps migration tests; };
+  passthru = {
+    inherit perlDeps;
+    tests.basic = nixosTests.hydra.hydra-unstable;
+  };
 
   meta = with lib; {
     description = "Nix-based continuous build system";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 8f432f8e43836..e98ae93e1fc57 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -17830,8 +17830,7 @@ with pkgs;
 
   hwloc = callPackage ../development/libraries/hwloc {};
 
-  inherit (callPackage ../development/tools/misc/hydra { })
-    hydra-unstable;
+  hydra-unstable = callPackage ../development/tools/misc/hydra/unstable.nix { nix = nixVersions.nix_2_6; };
 
   hydra-cli = callPackage ../development/tools/misc/hydra-cli { };