fix stack parse

src/trace.ts

@@ -6,17 +6,22 @@ interface StackFrame {
 const frameToString = ({ line, file, column }: StackFrame) =>
   `${file}:${line}:${column}`;
 
-const parseStackLine = (stackLine: string): StackFrame => {
+const parseStackLine = (stackLine: string): StackFrame | null => {
   const matches = RegExp(/\s+at\s+(.+\s)?\(?(.+):(\d+):(\d+)\)?/).exec(
     stackLine,
   );
-  if (!matches) throw new Error("could not figure out stack line");
+  if (!matches) {
+    console.error(`could not figure out stack line ${stackLine}`);
+    return null;
+  }
   const [, , file, line, column] = matches;
   return { file, line: parseInt(line), column: parseInt(column) };
 };
 
 const parseStackTrace = (trace: string, picker: (lines: string[]) => string) =>
   parseStackLine(picker(trace.split("\n")));
 
-export const currentLocation = (depth: number) =>
-  frameToString(parseStackTrace(new Error().stack as string, (x) => x[depth]));
+export const currentLocation = (depth: number) => {
+  const x = parseStackTrace(new Error().stack as string, (x) => x[depth]);
+  return x ? frameToString(x) : "stack line could not be parsed";
+};