Add allowed-to-fail CLI flag to round-tripping script

Author: ngernest

interp/src/main.rs

@@ -54,6 +54,10 @@ struct Cli {
     /// of cycles specified with this option.
     #[arg(long)]
     max_steps: Option<u32>,
+
+    /// Mark this test as allowed to fail (ignored by interpreter, used by test harness)
+    #[arg(long)]
+    allowed_to_fail: bool,
 }
 
 /// Examples (enables all tracing logs):

scripts/roundtrip_case.py

@@ -175,7 +175,8 @@ def format_monitor_trace_candidates(traces: list[list[str]]) -> str:
 
 
 def main() -> int:
-    """Execute one roundtrip check for a single `.tx` file."""
+    """Execute one roundtrip check for a single `.tx` file. If the
+    interpreter fails with a non-zero exit code, the test is skipped."""
     parser = argparse.ArgumentParser(
         description="Run one roundtrip check for a single .tx file."
     )
@@ -185,8 +186,17 @@ def main() -> int:
         action="store_true",
         help="Do not delete the intermediate .fst waveform file after the check",
     )
+    parser.add_argument(
+        "--allowed-to-fail",
+        action="store_true",
+        help="Mark this test as allowed to fail (will be skipped)",
+    )
     args_ns = parser.parse_args()
 
+    if args_ns.allowed_to_fail:
+        print("SKIP: allowed to fail")
+        return 0
+
     tx_file = Path(args_ns.tx_file).resolve()
     if not tx_file.exists():
         return fail(f"Missing tx file: {tx_file}")