1 files changed, 57 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/test/checkpointBuild/default.nix b/nixpkgs/pkgs/test/checkpointBuild/default.nix
new file mode 100644
index 000000000000..4a59760230a6
--- /dev/null
+++ b/nixpkgs/pkgs/test/checkpointBuild/default.nix
@@ -0,0 +1,57 @@
+{ hello, checkpointBuildTools, runCommandNoCC, texinfo, stdenv, rsync }:
+let
+  baseHelloArtifacts = checkpointBuildTools.prepareCheckpointBuild hello;
+  patchedHello = hello.overrideAttrs (old: {
+    buildInputs = [ texinfo ];
+    src = runCommandNoCC "patch-hello-src" { } ''
+      mkdir -p $out
+      cd $out
+      tar xf ${hello.src} --strip-components=1
+      patch -p1 < ${./hello.patch}
+    '';
+  });
+  checkpointBuiltHello = checkpointBuildTools.mkCheckpointedBuild patchedHello baseHelloArtifacts;
+
+  checkpointBuiltHelloWithCheck = checkpointBuiltHello.overrideAttrs (old: {
+    doCheck = true;
+    checkPhase = ''
+      echo "checking if unchanged source file is not recompiled"
+        [ "$(stat --format="%Y" lib/exitfail.o)" = "$(stat --format="%Y" ${baseHelloArtifacts}/outputs/lib/exitfail.o)" ]
+    '';
+  });
+
+  baseHelloRemoveFileArtifacts = checkpointBuildTools.prepareCheckpointBuild (hello.overrideAttrs (old: {
+    patches = [ ./hello-additionalFile.patch ];
+  }));
+
+  preparedHelloRemoveFileSrc = runCommandNoCC "patch-hello-src" { } ''
+    mkdir -p $out
+    cd $out
+    tar xf ${hello.src} --strip-components=1
+    patch -p1 < ${./hello-additionalFile.patch}
+  '';
+
+  patchedHelloRemoveFile = hello.overrideAttrs (old: {
+    buildInputs = [ texinfo ];
+    src = runCommandNoCC "patch-hello-src" { } ''
+      mkdir -p $out
+      cd $out
+      ${rsync}/bin/rsync -cutU --chown=$USER:$USER --chmod=+w -r ${preparedHelloRemoveFileSrc}/* .
+      patch -p1 < ${./hello-removeFile.patch}
+    '';
+  });
+
+  checkpointBuiltHelloWithRemovedFile = checkpointBuildTools.mkCheckpointedBuild patchedHelloRemoveFile baseHelloRemoveFileArtifacts;
+in
+stdenv.mkDerivation {
+  name = "patched-hello-returns-correct-output";
+  buildCommand = ''
+    touch $out
+
+    echo "testing output of hello binary"
+    [ "$(${checkpointBuiltHelloWithCheck}/bin/hello)" = "Hello, incremental world!" ]
+    echo "testing output of hello with removed file"
+    [ "$(${checkpointBuiltHelloWithRemovedFile}/bin/hello)" = "Hello, incremental world!" ]
+  '';
+}
+