Memchaser stopped working for Nightly builds

[whimboo]

There are two failures which I can see in the browser console:

11:18:40.119 memchaser:Exception { message: "Component returned failure code: 0x…", result: 2147500037, name: "NS_ERROR_FAILURE", filename: "resource://gre/modules/commonjs/too…", lineNumber: 70, columnNumber: 0, data: null, stack: "set dir@resource://gre/modules/comm…", location: XPCWrappedNative_NoHelper } runner.js:166
11:18:40.125 memchaser:Exception { message: "Component returned failure code: 0x…", result: 2147500037, name: "NS_ERROR_FAILURE", filename: "resource://gre/modules/commonjs/too…", lineNumber: 70, columnNumber: 0, data: null, stack: "set dir@resource://gre/modules/comm…", location: XPCWrappedNative_NoHelper } Promise-backend.js:940