Create test for issue 13247

This test ends up being skipped, since the bug has not yet been fixed. A
future commit will fix the bug.

Progress on #13247, naturally.

tests/functional/ca/issue-13247.nix

@@ -0,0 +1,46 @@
+with import ./config.nix;
+
+rec {
+
+  a = mkDerivation {
+    name = "issue-13247-a";
+    builder = builtins.toFile "builder.sh" ''
+      mkdir $out
+      test -z $all
+      echo "output" > $out/file
+    '';
+  };
+
+  # Same output, different drv
+  a-prime = mkDerivation {
+    name = "issue-13247-a";
+    builder = builtins.toFile "builder.sh" ''
+      echo 'will make the same stuff as `a`, but different drv hash'
+
+      mkdir $out
+      test -z $all
+      echo "output" > $out/file
+    '';
+  };
+
+  # Multiple outputs in a derivation that depends on other derivations
+  f =
+    dep:
+    mkDerivation {
+      name = "use-a-more-outputs";
+      outputs = [
+        "first"
+        "second"
+      ];
+      inherit dep;
+      builder = builtins.toFile "builder.sh" ''
+        ln -s $dep/file $first
+        ln -s $first $second
+      '';
+    };
+
+  use-a-more-outputs = f a;
+
+  use-a-prime-more-outputs = f a-prime;
+
+}

tests/functional/ca/issue-13247.sh

@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+
+# https://github.com/NixOS/nix/issues/13247
+
+export NIX_TESTS_CA_BY_DEFAULT=1
+
+source common.sh
+
+clearStoreIfPossible
+
+set -x
+
+# Build derivation (both outputs)
+nix build -f issue-13247.nix --json a a-prime use-a-more-outputs --no-link > "$TEST_ROOT"/a.json
+
+cache="file://$TEST_ROOT/cache"
+
+# Copy all outputs and realisations to cache
+declare -a drvs
+for d in "$NIX_STORE_DIR"/*-issue-13247-a.drv "$NIX_STORE_DIR"/*-use-a-more-outputs.drv; do
+    drvs+=("$d" "$d"^*)
+done
+nix copy --to "$cache" "${drvs[@]}"
+
+function delete () {
+    # Delete local copy
+    # shellcheck disable=SC2046
+    nix-store --delete \
+        $(jq -r <"$TEST_ROOT"/a.json '.[] | .drvPath, .outputs.[]') \
+        "$NIX_STORE_DIR"/*-issue-13247-a.drv \
+        "$NIX_STORE_DIR"/*-use-a-more-outputs.drv
+
+    [[ ! -e "$(jq -r <"$TEST_ROOT"/a.json '.[0].outputs.out')" ]]
+    [[ ! -e "$(jq -r <"$TEST_ROOT"/a.json '.[1].outputs.out')" ]]
+    [[ ! -e "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.first')" ]]
+    [[ ! -e "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.second')" ]]
+}
+
+delete
+
+buildViaSubstitute () {
+    nix build -f issue-13247.nix "$1" --no-link --max-jobs 0 --substituters "$cache" --no-require-sigs --offline --substitute
+}
+
+# Substitue just the first output
+buildViaSubstitute use-a-more-outputs^first
+
+# Should only fetch the output we asked for
+[[ -d "$(jq -r <"$TEST_ROOT"/a.json '.[0].outputs.out')" ]]
+[[ -f "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.first')" ]]
+[[ ! -e "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.second')" ]]
+
+delete
+
+# Failure with 2.28 encountered in CI
+requireDaemonNewerThan "2.29"
+
+# Substitue just the first output
+#
+# This derivation is the same after normalization, so we should get
+# early cut-off, and thus a chance to download just the output we want
+# rather than building more
+buildViaSubstitute use-a-prime-more-outputs^first
+
+# Should only fetch the output we asked for
+[[ -d "$(jq -r <"$TEST_ROOT"/a.json '.[0].outputs.out')" ]]
+[[ -f "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.first')" ]]
+
+# Output should *not* be here, this is the bug
+[[ -e "$(jq -r <"$TEST_ROOT"/a.json '.[2].outputs.second')" ]]
+skipTest "bug is not yet fixed"

tests/functional/ca/meson.build

@@ -19,6 +19,7 @@ suites += {
     'eval-store.sh',
     'gc.sh',
     'import-from-derivation.sh',
+    'issue-13247.sh',
     'multiple-outputs.sh',
     'new-build-cmd.sh',
     'nix-copy.sh',