Fix derivation computation with __structuredAttrs and multiple outputs

Fixes

  error: derivation '/nix/store/klivma7r7h5lndb99f7xxmlh5whyayvg-zlib-1.2.11.drv' has incorrect output '/nix/store/fv98nnx5ykgbq8sqabilkgkbc4169q05-zlib-1.2.11-dev', should be '/nix/store/adm7pilzlj3z5k249s8b4wv3scprhzi1-zlib-1.2.11-dev'

src/libexpr/primops.cc

@@ -731,6 +731,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
            the hash. */
         for (auto & i : outputs) {
             if (!jsonObject) drv.env[i] = "";
+            drv.outputs.insert_or_assign(i,
+                DerivationOutput(StorePath::dummy.clone(), "", ""));
         }
 
         Hash h = hashDerivationModulo(*state.store, Derivation(drv), true);

src/libstore/derivations.cc

@@ -246,30 +246,18 @@ string Derivation::unparse(const Store & store, bool maskOutputs,
     s.reserve(65536);
     s += "Derive([";
 
-    StringSet maskedOutputs;
-
-    if (maskOutputs) {
-        bool first = true;
-        maskedOutputs = tokenizeString<StringSet>(get(env, "outputs").value_or("out"), " ");
-        for (auto & i : maskedOutputs) {
-            if (first) first = false; else s += ',';
-            s += '('; printString(s, i);
-            s += ",\"\",\"\",\"\")";
-        }
-    } else {
     bool first = true;
     for (auto & i : outputs) {
         if (first) first = false; else s += ',';
         s += '('; printString(s, i.first);
-            s += ','; printString(s, store.printStorePath(i.second.path));
+        s += ','; printString(s, maskOutputs ? "" : store.printStorePath(i.second.path));
         s += ','; printString(s, i.second.hashAlgo);
         s += ','; printString(s, i.second.hash);
         s += ')';
     }
-    }
 
     s += "],[";
-    bool first = true;
+    first = true;
     if (actualInputs) {
         for (auto & i : *actualInputs) {
             if (first) first = false; else s += ',';
@@ -299,7 +287,7 @@ string Derivation::unparse(const Store & store, bool maskOutputs,
     for (auto & i : env) {
         if (first) first = false; else s += ',';
         s += '('; printString(s, i.first);
-        s += ','; printString(s, maskOutputs && maskedOutputs.count(i.first) ? "" : i.second);
+        s += ','; printString(s, maskOutputs && outputs.count(i.first) ? "" : i.second);
         s += ')';
     }
 

src/libstore/nar-info.cc

@@ -4,7 +4,7 @@
 namespace nix {
 
 NarInfo::NarInfo(const Store & store, const std::string & s, const std::string & whence)
-    : ValidPathInfo(StorePath::make((unsigned char *) "xxxxxxxxxxxxxxxxxxxx", "x")) // FIXME: hack
+    : ValidPathInfo(StorePath::dummy.clone()) // FIXME: hack
 {
     auto corrupt = [&]() {
         throw Error(format("NAR info file '%1%' is corrupt") % whence);

src/libstore/path.cc

@@ -46,12 +46,15 @@ std::string_view StorePath::name() const
     return ffi_StorePath_name(*this);
 }
 
+StorePath StorePath::dummy(
+    StorePath::make(
+        (unsigned char *) "xxxxxxxxxxxxxxxxxxxx", "x"));
+
 StorePath Store::parseStorePath(std::string_view path) const
 {
     return StorePath::make(path, storeDir);
 }
 
-
 StorePathSet Store::parseStorePathSet(const PathSet & paths) const
 {
     StorePathSet res;

src/libstore/path.hh

@@ -53,6 +53,8 @@ struct StorePath : rust::Value<3 * sizeof(void *) + 24, ffi_StorePath_drop>
     {
         return ffi_StorePath_hash_data(*this);
     }
+
+    static StorePath dummy;
 };
 
 typedef std::set<StorePath> StorePathSet;

tests/structured-attrs.nix

@@ -16,6 +16,8 @@ mkDerivation {
 
   __structuredAttrs = true;
 
+  outputs = [ "out" "dev" ];
+
   buildCommand = ''
     set -x
 
@@ -30,8 +32,9 @@ mkDerivation {
     [[ -v nothing ]]
     [[ -z $nothing ]]
 
-    mkdir ''${outputs[out]}
+    mkdir ''${outputs[out]} ''${outputs[dev]}
     echo bar > $dest
+    echo foo > $dest2
 
     json=$(cat .attrs.json)
     [[ $json =~ '"narHash":"sha256:1r7yc43zqnzl5b0als5vnyp649gk17i37s7mj00xr8kc47rjcybk"' ]]
@@ -57,6 +60,7 @@ mkDerivation {
   nothing = null;
 
   dest = "${placeholder "out"}/foo";
+  dest2 = "${placeholder "dev"}/foo";
 
   "foo bar" = "BAD";
   "1foobar" = "BAD";

tests/structured-attrs.sh

@@ -2,6 +2,7 @@ source common.sh
 
 clearStore
 
-outPath=$(nix-build structured-attrs.nix --no-out-link)
+nix-build structured-attrs.nix -A all -o $TEST_ROOT/result
 
-[[ $(cat $outPath/foo) = bar ]]
+[[ $(cat $TEST_ROOT/result/foo) = bar ]]
+[[ $(cat $TEST_ROOT/result-dev/foo) = foo ]]