Provide more error context when a runtime benchmark group fails to compile

Author: Kobzol

collector/src/runtime/benchmark.rs

@@ -135,7 +135,16 @@ pub struct BenchmarkSuiteCompilation {
 
 impl BenchmarkSuiteCompilation {
     pub fn extract_suite(self) -> BenchmarkSuite {
-        assert!(self.failed_to_compile.is_empty());
+        use std::fmt::Write;
+
+        if !self.failed_to_compile.is_empty() {
+            let mut message =
+                "Cannot extract runtime suite because of compilation errors:\n".to_string();
+            for (group, error) in self.failed_to_compile {
+                writeln!(message, "{group}\n{error}\n").unwrap();
+            }
+            panic!("{message}");
+        }
         self.suite
     }
 }