diff --git a/src/tools/rust-analyzer/crates/proc-macro-srv/src/tests/mod.rs b/src/tools/rust-analyzer/crates/proc-macro-srv/src/tests/mod.rs
index 968e88700067..1e2e8da60cde 100644
--- a/src/tools/rust-analyzer/crates/proc-macro-srv/src/tests/mod.rs
+++ b/src/tools/rust-analyzer/crates/proc-macro-srv/src/tests/mod.rs
@@ -10,16 +10,44 @@
 fn test_derive_empty() {
     assert_expand(
         "DeriveEmpty",
-        r#"struct S;"#,
+        r#"struct S { field: &'r#lt fn(u32) -> &'a r#u32 }"#,
         expect![[r#"
             IDENT 1 struct
             IDENT 1 S
-            PUNCT 1 ; [alone]
+            GROUP {} 1 1 1
+              IDENT 1 field
+              PUNCT 1 : [alone]
+              PUNCT 1 & [joint]
+              PUNCT 1 ' [joint]
+              IDENT 1 r#lt
+              IDENT 1 fn
+              GROUP () 1 1 1
+                IDENT 1 u32
+              PUNCT 1 - [joint]
+              PUNCT 1 > [alone]
+              PUNCT 1 & [joint]
+              PUNCT 1 ' [joint]
+              IDENT 1 a
+              IDENT 1 r#u32
         "#]],
         expect![[r#"
             IDENT 42:Root[0000, 0]@0..6#ROOT2024 struct
             IDENT 42:Root[0000, 0]@7..8#ROOT2024 S
-            PUNCT 42:Root[0000, 0]@8..9#ROOT2024 ; [alone]
+            GROUP {} 42:Root[0000, 0]@9..10#ROOT2024 42:Root[0000, 0]@46..47#ROOT2024 42:Root[0000, 0]@9..47#ROOT2024
+              IDENT 42:Root[0000, 0]@11..16#ROOT2024 field
+              PUNCT 42:Root[0000, 0]@16..17#ROOT2024 : [alone]
+              PUNCT 42:Root[0000, 0]@18..19#ROOT2024 & [joint]
+              PUNCT 42:Root[0000, 0]@22..23#ROOT2024 ' [joint]
+              IDENT 42:Root[0000, 0]@22..24#ROOT2024 r#lt
+              IDENT 42:Root[0000, 0]@25..27#ROOT2024 fn
+              GROUP () 42:Root[0000, 0]@27..28#ROOT2024 42:Root[0000, 0]@31..32#ROOT2024 42:Root[0000, 0]@27..32#ROOT2024
+                IDENT 42:Root[0000, 0]@28..31#ROOT2024 u32
+              PUNCT 42:Root[0000, 0]@33..34#ROOT2024 - [joint]
+              PUNCT 42:Root[0000, 0]@34..35#ROOT2024 > [alone]
+              PUNCT 42:Root[0000, 0]@36..37#ROOT2024 & [joint]
+              PUNCT 42:Root[0000, 0]@38..39#ROOT2024 ' [joint]
+              IDENT 42:Root[0000, 0]@38..39#ROOT2024 a
+              IDENT 42:Root[0000, 0]@42..45#ROOT2024 r#u32
         "#]],
     );
 }
@@ -466,6 +494,30 @@ fn test_attr_macro() {
     );
 }
 
+#[test]
+#[should_panic = "called `Result::unwrap()` on an `Err` value: \"Mismatched token groups\""]
+fn test_broken_input_unclosed_delim() {
+    assert_expand("fn_like_clone_tokens", r###"{"###, expect![[]], expect![[]]);
+}
+
+#[test]
+#[should_panic = "called `Result::unwrap()` on an `Err` value: \"Unexpected '}'\""]
+fn test_broken_input_unopened_delim() {
+    assert_expand("fn_like_clone_tokens", r###"}"###, expect![[]], expect![[]]);
+}
+
+#[test]
+#[should_panic = "called `Result::unwrap()` on an `Err` value: \"Expected '}'\""]
+fn test_broken_input_mismatched_delim() {
+    assert_expand("fn_like_clone_tokens", r###"(}"###, expect![[]], expect![[]]);
+}
+
+#[test]
+#[should_panic = "called `Result::unwrap()` on an `Err` value: \"Invalid identifier: `🪟`\""]
+fn test_broken_input_unknowm_token() {
+    assert_expand("fn_like_clone_tokens", r###"🪟"###, expect![[]], expect![[]]);
+}
+
 /// Tests that we find and classify all proc macros correctly.
 #[test]
 fn list_test_macros() {
diff --git a/src/tools/rust-analyzer/crates/proc-macro-srv/src/token_stream.rs b/src/tools/rust-analyzer/crates/proc-macro-srv/src/token_stream.rs
index cfdf0da903f9..628d6942392c 100644
--- a/src/tools/rust-analyzer/crates/proc-macro-srv/src/token_stream.rs
+++ b/src/tools/rust-analyzer/crates/proc-macro-srv/src/token_stream.rs
@@ -98,7 +98,11 @@ pub(crate) fn from_str(s: &str, span: S) -> Result<Self, String>
                     groups.push((proc_macro::Delimiter::Parenthesis, range, vec![]))
                 }
                 rustc_lexer::TokenKind::CloseParen if *open_delim != Delimiter::Parenthesis => {
-                    return Err("Expected ')'".to_owned());
+                    return if *open_delim == Delimiter::None {
+                        Err("Unexpected ')'".to_owned())
+                    } else {
+                        Err("Expected ')'".to_owned())
+                    };
                 }
                 rustc_lexer::TokenKind::CloseParen => {
                     let (delimiter, open_range, stream) = groups.pop().unwrap();
@@ -122,7 +126,11 @@ pub(crate) fn from_str(s: &str, span: S) -> Result<Self, String>
                     groups.push((proc_macro::Delimiter::Brace, range, vec![]))
                 }
                 rustc_lexer::TokenKind::CloseBrace if *open_delim != Delimiter::Brace => {
-                    return Err("Expected '}'".to_owned());
+                    return if *open_delim == Delimiter::None {
+                        Err("Unexpected '}'".to_owned())
+                    } else {
+                        Err("Expected '}'".to_owned())
+                    };
                 }
                 rustc_lexer::TokenKind::CloseBrace => {
                     let (delimiter, open_range, stream) = groups.pop().unwrap();
@@ -146,7 +154,11 @@ pub(crate) fn from_str(s: &str, span: S) -> Result<Self, String>
                     groups.push((proc_macro::Delimiter::Bracket, range, vec![]))
                 }
                 rustc_lexer::TokenKind::CloseBracket if *open_delim != Delimiter::Bracket => {
-                    return Err("Expected ']'".to_owned());
+                    return if *open_delim == Delimiter::None {
+                        Err("Unexpected ']'".to_owned())
+                    } else {
+                        Err("Expected ']'".to_owned())
+                    };
                 }
                 rustc_lexer::TokenKind::CloseBracket => {
                     let (delimiter, open_range, stream) = groups.pop().unwrap();
@@ -223,10 +235,14 @@ pub(crate) fn from_str(s: &str, span: S) -> Result<Self, String>
                 }
                 rustc_lexer::TokenKind::Whitespace => continue,
                 rustc_lexer::TokenKind::Frontmatter { .. } => unreachable!(),
-                rustc_lexer::TokenKind::Unknown => return Err("Unknown token".to_owned()),
-                rustc_lexer::TokenKind::UnknownPrefix => return Err("Unknown prefix".to_owned()),
+                rustc_lexer::TokenKind::Unknown => {
+                    return Err(format!("Unknown token: `{}`", &s[range]));
+                }
+                rustc_lexer::TokenKind::UnknownPrefix => {
+                    return Err(format!("Unknown prefix: `{}`", &s[range]));
+                }
                 rustc_lexer::TokenKind::UnknownPrefixLifetime => {
-                    return Err("Unknown lifetime prefix".to_owned());
+                    return Err(format!("Unknown lifetime prefix: `{}`", &s[range]));
                 }
                 // FIXME: Error on edition >= 2024 ... I dont think the proc-macro server can fetch editions currently
                 // and whose edition is this?
@@ -247,7 +263,9 @@ pub(crate) fn from_str(s: &str, span: S) -> Result<Self, String>
                     is_raw: false,
                     span: span.derive_ranged(range),
                 })),
-                rustc_lexer::TokenKind::InvalidIdent => return Err("Invalid identifier".to_owned()),
+                rustc_lexer::TokenKind::InvalidIdent => {
+                    return Err(format!("Invalid identifier: `{}`", &s[range]));
+                }
                 rustc_lexer::TokenKind::RawIdent => {
                     let range = range.start + 2..range.end;
                     tokenstream.push(TokenTree::Ident(Ident {
diff --git a/src/tools/rust-analyzer/xtask/src/tidy.rs b/src/tools/rust-analyzer/xtask/src/tidy.rs
index ebfc7d0a9430..05528505f280 100644
--- a/src/tools/rust-analyzer/xtask/src/tidy.rs
+++ b/src/tools/rust-analyzer/xtask/src/tidy.rs
@@ -194,6 +194,7 @@ fn check_test_attrs(path: &Path, text: &str) {
         "test-utils/src/fixture.rs",
         // Generated code from lints contains doc tests in string literals.
         "ide-db/src/generated/lints.rs",
+        "proc-macro-srv/src/tests/mod.rs",
     ];
     if need_panic.iter().any(|p| path.ends_with(p)) {
         return;