Index: frontend/node_modules/stack-utils/index.js
===================================================================
--- frontend/node_modules/stack-utils/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/stack-utils/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,344 @@
+'use strict';
+
+const escapeStringRegexp = require('escape-string-regexp');
+
+const cwd = typeof process === 'object' && process && typeof process.cwd === 'function'
+  ? process.cwd()
+  : '.'
+
+const natives = [].concat(
+  require('module').builtinModules,
+  'bootstrap_node',
+  'node',
+).map(n => new RegExp(`(?:\\((?:node:)?${n}(?:\\.js)?:\\d+:\\d+\\)$|^\\s*at (?:node:)?${n}(?:\\.js)?:\\d+:\\d+$)`));
+
+natives.push(
+  /\((?:node:)?internal\/[^:]+:\d+:\d+\)$/,
+  /\s*at (?:node:)?internal\/[^:]+:\d+:\d+$/,
+  /\/\.node-spawn-wrap-\w+-\w+\/node:\d+:\d+\)?$/
+);
+
+class StackUtils {
+  constructor (opts) {
+    opts = {
+      ignoredPackages: [],
+      ...opts
+    };
+
+    if ('internals' in opts === false) {
+      opts.internals = StackUtils.nodeInternals();
+    }
+
+    if ('cwd' in opts === false) {
+      opts.cwd = cwd
+    }
+
+    this._cwd = opts.cwd.replace(/\\/g, '/');
+    this._internals = [].concat(
+      opts.internals,
+      ignoredPackagesRegExp(opts.ignoredPackages)
+    );
+
+    this._wrapCallSite = opts.wrapCallSite || false;
+  }
+
+  static nodeInternals () {
+    return [...natives];
+  }
+
+  clean (stack, indent = 0) {
+    indent = ' '.repeat(indent);
+
+    if (!Array.isArray(stack)) {
+      stack = stack.split('\n');
+    }
+
+    if (!(/^\s*at /.test(stack[0])) && (/^\s*at /.test(stack[1]))) {
+      stack = stack.slice(1);
+    }
+
+    let outdent = false;
+    let lastNonAtLine = null;
+    const result = [];
+
+    stack.forEach(st => {
+      st = st.replace(/\\/g, '/');
+
+      if (this._internals.some(internal => internal.test(st))) {
+        return;
+      }
+
+      const isAtLine = /^\s*at /.test(st);
+
+      if (outdent) {
+        st = st.trimEnd().replace(/^(\s+)at /, '$1');
+      } else {
+        st = st.trim();
+        if (isAtLine) {
+          st = st.slice(3);
+        }
+      }
+
+      st = st.replace(`${this._cwd}/`, '');
+
+      if (st) {
+        if (isAtLine) {
+          if (lastNonAtLine) {
+            result.push(lastNonAtLine);
+            lastNonAtLine = null;
+          }
+
+          result.push(st);
+        } else {
+          outdent = true;
+          lastNonAtLine = st;
+        }
+      }
+    });
+
+    return result.map(line => `${indent}${line}\n`).join('');
+  }
+
+  captureString (limit, fn = this.captureString) {
+    if (typeof limit === 'function') {
+      fn = limit;
+      limit = Infinity;
+    }
+
+    const {stackTraceLimit} = Error;
+    if (limit) {
+      Error.stackTraceLimit = limit;
+    }
+
+    const obj = {};
+
+    Error.captureStackTrace(obj, fn);
+    const {stack} = obj;
+    Error.stackTraceLimit = stackTraceLimit;
+
+    return this.clean(stack);
+  }
+
+  capture (limit, fn = this.capture) {
+    if (typeof limit === 'function') {
+      fn = limit;
+      limit = Infinity;
+    }
+
+    const {prepareStackTrace, stackTraceLimit} = Error;
+    Error.prepareStackTrace = (obj, site) => {
+      if (this._wrapCallSite) {
+        return site.map(this._wrapCallSite);
+      }
+
+      return site;
+    };
+
+    if (limit) {
+      Error.stackTraceLimit = limit;
+    }
+
+    const obj = {};
+    Error.captureStackTrace(obj, fn);
+    const { stack } = obj;
+    Object.assign(Error, {prepareStackTrace, stackTraceLimit});
+
+    return stack;
+  }
+
+  at (fn = this.at) {
+    const [site] = this.capture(1, fn);
+
+    if (!site) {
+      return {};
+    }
+
+    const res = {
+      line: site.getLineNumber(),
+      column: site.getColumnNumber()
+    };
+
+    setFile(res, site.getFileName(), this._cwd);
+
+    if (site.isConstructor()) {
+      Object.defineProperty(res, 'constructor', {
+        value: true,
+        configurable: true,
+      });
+    }
+
+    if (site.isEval()) {
+      res.evalOrigin = site.getEvalOrigin();
+    }
+
+    // Node v10 stopped with the isNative() on callsites, apparently
+    /* istanbul ignore next */
+    if (site.isNative()) {
+      res.native = true;
+    }
+
+    let typename;
+    try {
+      typename = site.getTypeName();
+    } catch (_) {
+    }
+
+    if (typename && typename !== 'Object' && typename !== '[object Object]') {
+      res.type = typename;
+    }
+
+    const fname = site.getFunctionName();
+    if (fname) {
+      res.function = fname;
+    }
+
+    const meth = site.getMethodName();
+    if (meth && fname !== meth) {
+      res.method = meth;
+    }
+
+    return res;
+  }
+
+  parseLine (line) {
+    const match = line && line.match(re);
+    if (!match) {
+      return null;
+    }
+
+    const ctor = match[1] === 'new';
+    let fname = match[2];
+    const evalOrigin = match[3];
+    const evalFile = match[4];
+    const evalLine = Number(match[5]);
+    const evalCol = Number(match[6]);
+    let file = match[7];
+    const lnum = match[8];
+    const col = match[9];
+    const native = match[10] === 'native';
+    const closeParen = match[11] === ')';
+    let method;
+
+    const res = {};
+
+    if (lnum) {
+      res.line = Number(lnum);
+    }
+
+    if (col) {
+      res.column = Number(col);
+    }
+
+    if (closeParen && file) {
+      // make sure parens are balanced
+      // if we have a file like "asdf) [as foo] (xyz.js", then odds are
+      // that the fname should be += " (asdf) [as foo]" and the file
+      // should be just "xyz.js"
+      // walk backwards from the end to find the last unbalanced (
+      let closes = 0;
+      for (let i = file.length - 1; i > 0; i--) {
+        if (file.charAt(i) === ')') {
+          closes++;
+        } else if (file.charAt(i) === '(' && file.charAt(i - 1) === ' ') {
+          closes--;
+          if (closes === -1 && file.charAt(i - 1) === ' ') {
+            const before = file.slice(0, i - 1);
+            const after = file.slice(i + 1);
+            file = after;
+            fname += ` (${before}`;
+            break;
+          }
+        }
+      }
+    }
+
+    if (fname) {
+      const methodMatch = fname.match(methodRe);
+      if (methodMatch) {
+        fname = methodMatch[1];
+        method = methodMatch[2];
+      }
+    }
+
+    setFile(res, file, this._cwd);
+
+    if (ctor) {
+      Object.defineProperty(res, 'constructor', {
+        value: true,
+        configurable: true,
+      });
+    }
+
+    if (evalOrigin) {
+      res.evalOrigin = evalOrigin;
+      res.evalLine = evalLine;
+      res.evalColumn = evalCol;
+      res.evalFile = evalFile && evalFile.replace(/\\/g, '/');
+    }
+
+    if (native) {
+      res.native = true;
+    }
+
+    if (fname) {
+      res.function = fname;
+    }
+
+    if (method && fname !== method) {
+      res.method = method;
+    }
+
+    return res;
+  }
+}
+
+function setFile (result, filename, cwd) {
+  if (filename) {
+    filename = filename.replace(/\\/g, '/');
+    if (filename.startsWith(`${cwd}/`)) {
+      filename = filename.slice(cwd.length + 1);
+    }
+
+    result.file = filename;
+  }
+}
+
+function ignoredPackagesRegExp(ignoredPackages) {
+  if (ignoredPackages.length === 0) {
+    return [];
+  }
+
+  const packages = ignoredPackages.map(mod => escapeStringRegexp(mod));
+
+  return new RegExp(`[\/\\\\]node_modules[\/\\\\](?:${packages.join('|')})[\/\\\\][^:]+:\\d+:\\d+`)
+}
+
+const re = new RegExp(
+  '^' +
+    // Sometimes we strip out the '    at' because it's noisy
+  '(?:\\s*at )?' +
+    // $1 = ctor if 'new'
+  '(?:(new) )?' +
+    // $2 = function name (can be literally anything)
+    // May contain method at the end as [as xyz]
+  '(?:(.*?) \\()?' +
+    // (eval at <anonymous> (file.js:1:1),
+    // $3 = eval origin
+    // $4:$5:$6 are eval file/line/col, but not normally reported
+  '(?:eval at ([^ ]+) \\((.+?):(\\d+):(\\d+)\\), )?' +
+    // file:line:col
+    // $7:$8:$9
+    // $10 = 'native' if native
+  '(?:(.+?):(\\d+):(\\d+)|(native))' +
+    // maybe close the paren, then end
+    // if $11 is ), then we only allow balanced parens in the filename
+    // any imbalance is placed on the fname.  This is a heuristic, and
+    // bound to be incorrect in some edge cases.  The bet is that
+    // having weird characters in method names is more common than
+    // having weird characters in filenames, which seems reasonable.
+  '(\\)?)$'
+);
+
+const methodRe = /^(.*?) \[as (.*?)\]$/;
+
+module.exports = StackUtils;