babel-core SyntaxError: Unexpected token

Hello,

Randomly meteor-client-bundler has stopped working for me. When trying to bundle I get the following error:

xxx/node_modules/babel-core/lib/transformation/file/index.js:558
      throw err;
      ^

SyntaxError: /var/folders/hc/7hpp_2jj0s178gbdhqwyyq8w0000gn/T/tmp-99511oI8C9JMD3EM/bundle/programs/web.browser/packages/modules.js: Unexpected token (34842:18)
  34840 | const REMOVED_MARKER = '______MONGO_OBJECT_REMOVED______';
  34841 | class MongoObject {
> 34842 |     _affectedKeys = {};
        |                   ^
  34843 |     _arrayItemPositions = [];
  34844 |     _blackboxKeys = [];
  34845 |     _genericAffectedKeys = {};
    at Parser.pp$5.raise (xxx/node_modules/babylon/lib/index.js:4454:13)
    at Parser.pp.unexpected (xxx/node_modules/babylon/lib/index.js:1761:8)
    at Parser.pp$1.parseClassProperty (xxx/node_modules/babylon/lib/index.js:2571:50)
    at Parser.pp$1.parseClassBody (xxx/node_modules/babylon/lib/index.js:2516:34)
    at Parser.pp$1.parseClass (xxx/node_modules/babylon/lib/index.js:2406:8)
    at Parser.pp$1.parseStatement (xxx/node_modules/babylon/lib/index.js:1843:19)
    at Parser.pp$1.parseBlockBody (xxx/node_modules/babylon/lib/index.js:2268:21)
    at Parser.pp$1.parseBlock (xxx/node_modules/babylon/lib/index.js:2247:8)
    at Parser.pp$3.parseFunctionBody xxx/node_modules/babylon/lib/index.js:4235:22)
    at Parser.pp$1.parseFunction (xxx/node_modules/babylon/lib/index.js:2386:8) {
  pos: 1346687,
  loc: Position { line: 34842, column: 18 },
  _babel: true,
  codeFrame: "\x1B[0m \x1B[90m 34840 | \x1B[39m\x1B[36mconst\x1B[39m \x1B[33mREMOVED_MARKER\x1B[39m \x1B[33m=\x1B[39m \x1B[32m'______MONGO_OBJECT_REMOVED______'\x1B[39m\x1B[33m;\x1B[39m\n" +
    ' \x1B[90m 34841 | \x1B[39m\x1B[36mclass\x1B[39m \x1B[33mMongoObject\x1B[39m {\n' +
    '\x1B[31m\x1B[1m>\x1B[22m\x1B[39m\x1B[90m 34842 | \x1B[39m    _affectedKeys \x1B[33m=\x1B[39m {}\x1B[33m;\x1B[39m\n' +
    ' \x1B[90m       | \x1B[39m                  \x1B[31m\x1B[1m^\x1B[22m\x1B[39m\n' +
    ' \x1B[90m 34843 | \x1B[39m    _arrayItemPositions \x1B[33m=\x1B[39m []\x1B[33m;\x1B[39m\n' +
    ' \x1B[90m 34844 | \x1B[39m    _blackboxKeys \x1B[33m=\x1B[39m []\x1B[33m;\x1B[39m\n' +
    ' \x1B[90m 34845 | \x1B[39m    _genericAffectedKeys \x1B[33m=\x1B[39m {}\x1B[33m;\x1B[39m\x1B[0m'
}

I am using version 0.6.0.

I have tried:

Cloned a previously working branch
Deleted node_modules
Deleted .meteor
Updated meteor to 2.8.0
Reinstalled meteor-client-bundler

Issue seems similar to: https://github.com/Urigo/meteor-client-bundler/issues/68

Urigo / meteor-client-bundler

babel-core SyntaxError: Unexpected token #138