fix: correct error count for cargo check --message-format json

src/cargo/core/compiler/mod.rs

@@ -1742,6 +1742,33 @@ fn on_stderr_line_inner(
         return Ok(true);
     }
 
+    #[derive(serde::Deserialize)]
+    struct CompilerMessage {
+        rendered: String,
+        message: String,
+        level: String,
+        children: Vec<PartialDiagnostic>,
+    }
+
+    // A partial rustfix::diagnostics::Diagnostic. We deserialize only a
+    // subset of the fields because rustc's output can be extremely
+    // deeply nested JSON in pathological cases involving macro
+    // expansion. Rustfix's Diagnostic struct is recursive containing a
+    // field `children: Vec<Self>`, and it can cause deserialization to
+    // hit serde_json's default recursion limit, or overflow the stack
+    // if we turn that off. Cargo only cares about the 1 field listed
+    // here.
+    #[derive(serde::Deserialize)]
+    struct PartialDiagnostic {
+        spans: Vec<PartialDiagnosticSpan>,
+    }
+
+    // A partial rustfix::diagnostics::DiagnosticSpan.
+    #[derive(serde::Deserialize)]
+    struct PartialDiagnosticSpan {
+        suggestion_applicability: Option<Applicability>,
+    }
+
     // Depending on what we're emitting from Cargo itself, we figure out what to
     // do with this JSON message.
     match options.format {
@@ -1755,33 +1782,6 @@ fn on_stderr_line_inner(
             render_diagnostics: true,
             ..
         } => {
-            #[derive(serde::Deserialize)]
-            struct CompilerMessage {
-                rendered: String,
-                message: String,
-                level: String,
-                children: Vec<PartialDiagnostic>,
-            }
-
-            // A partial rustfix::diagnostics::Diagnostic. We deserialize only a
-            // subset of the fields because rustc's output can be extremely
-            // deeply nested JSON in pathological cases involving macro
-            // expansion. Rustfix's Diagnostic struct is recursive containing a
-            // field `children: Vec<Self>`, and it can cause deserialization to
-            // hit serde_json's default recursion limit, or overflow the stack
-            // if we turn that off. Cargo only cares about the 1 field listed
-            // here.
-            #[derive(serde::Deserialize)]
-            struct PartialDiagnostic {
-                spans: Vec<PartialDiagnosticSpan>,
-            }
-
-            // A partial rustfix::diagnostics::DiagnosticSpan.
-            #[derive(serde::Deserialize)]
-            struct PartialDiagnosticSpan {
-                suggestion_applicability: Option<Applicability>,
-            }
-
             if let Ok(mut msg) = serde_json::from_str::<CompilerMessage>(compiler_message.get()) {
                 if msg.message.starts_with("aborting due to")
                     || msg.message.ends_with("warning emitted")
@@ -1865,12 +1865,15 @@ fn on_stderr_line_inner(
         return Ok(true);
     }
 
-    #[derive(serde::Deserialize)]
-    struct CompilerMessage {
-        level: String,
-    }
-    if let Ok(message) = serde_json::from_str::<CompilerMessage>(compiler_message.get()) {
-        count_diagnostic(&message.level, options);
+    if let Ok(msg) = serde_json::from_str::<CompilerMessage>(compiler_message.get()) {
+        if msg.message.starts_with("aborting due to")
+            || msg.message.ends_with("warning emitted")
+            || msg.message.ends_with("warnings emitted")
+        {
+            // Skip this line; we'll print our own summary at the end.
+            return Ok(true);
+        }
+        count_diagnostic(&msg.level, options);
     }
 
     let msg = machine_message::FromCompiler {

tests/testsuite/build.rs

@@ -95,7 +95,7 @@ fn cargo_fail_with_no_stderr() {
         .with_status(101)
         .with_stderr_data(str![[r#"
 [COMPILING] foo v0.5.0 ([ROOT]/foo)
-[ERROR] could not compile `foo` (bin "foo") due to 2 previous errors
+[ERROR] could not compile `foo` (bin "foo") due to 1 previous error
 
 "#]])
         .run();

tests/testsuite/pkgid.rs

@@ -327,12 +327,6 @@ fn pkgid_json_message_metadata_consistency() {
     "reason": "compiler-message",
     "...": "{...}"
   },
-  {
-    "manifest_path": "[ROOT]/foo/Cargo.toml",
-    "package_id": "path+[ROOTURL]/foo#0.5.0",
-    "reason": "compiler-message",
-    "...": "{...}"
-  },
   {
     "manifest_path": "[ROOT]/foo/Cargo.toml",
     "package_id": "path+[ROOTURL]/foo#0.5.0",