1 files changed, 11 insertions, 0 deletions
diff --git a/src/test/ui/macros/issue-86865.rs b/src/test/ui/macros/issue-86865.rs
new file mode 100644
index 000000000..01e0a20a5
--- /dev/null
+++ b/src/test/ui/macros/issue-86865.rs
@@ -0,0 +1,11 @@
+use std::fmt::Write;
+
+fn main() {
+    println!(b"foo");
+    //~^ ERROR format argument must be a string literal
+    //~| HELP consider removing the leading `b`
+    let mut s = String::new();
+    write!(s, b"foo{}", "bar");
+    //~^ ERROR format argument must be a string literal
+    //~| HELP consider removing the leading `b`
+}