Merge pull request #8490 from flox/stdin_handling

fix: Do not apply default installables when using --stdin

src/libcmd/installables.cc

@@ -701,7 +701,7 @@ RawInstallablesCommand::RawInstallablesCommand()
 {
     addFlag({
         .longName = "stdin",
-        .description = "Read installables from the standard input.",
+        .description = "Read installables from the standard input. No default installable applied.",
         .handler = {&readFromStdIn, true}
     });
 
@@ -730,9 +730,9 @@ void RawInstallablesCommand::run(ref<Store> store)
         while (std::cin >> word) {
             rawInstallables.emplace_back(std::move(word));
         }
+    } else {
+        applyDefaultInstallables(rawInstallables);
     }
-
-    applyDefaultInstallables(rawInstallables);
     run(store, std::move(rawInstallables));
 }
 

tests/build.sh

@@ -129,3 +129,7 @@ nix build --impure -f multiple-outputs.nix --json e --no-link | jq --exit-status
     (.drvPath | match(".*multiple-outputs-e.drv")) and
     (.outputs | keys == ["a_a", "b"]))
 '
+
+# Make sure that `--stdin` works and does not apply any defaults
+printf "" | nix build --no-link --stdin --json | jq --exit-status '. == []'
+printf "%s\n" "$drv^*" | nix build --no-link --stdin --json | jq --exit-status '.[0]|has("drvPath")'