Do not bold main message in `--error-format=short`

Fix #63835.

1 files changed, 8 insertions, 1 deletions

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 922846775f6..a11213aaca8 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1348,7 +1348,14 @@ impl EmitterWriter {
                 buffer.append(0, "]", Style::Level(*level));
                 label_width += 2 + code.len();
             }
-            let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
+            let header_style = if is_secondary {
+                Style::HeaderMsg
+            } else if self.short_message {
+                // For short messages avoid bolding the message, as it doesn't look great (#63835).
+                Style::NoStyle
+            } else {
+                Style::MainHeaderMsg
+            };
             if *level != Level::FailureNote {
                 buffer.append(0, ": ", header_style);
                 label_width += 2;