message: Attempt to reproduce
  No luck...
diff: @@ -1475,6 +1475,16 @@ function defineRecognizerSpecs(
  })
  it("can use serialized grammar in performSelfAnalysis", () => {
  + // Attempt to reproduce
  + // https://github.com/SAP/chevrotain/issues/952
  + const PlusTok = createToken({
  + name: "PlusTok",
  + pattern: {
  + exec: (text, offset) =>
  + /\+/.exec(text.substring(offset))
  + }
  + })
  +
  let serializedGrammar = null
  class SerializingParser extends Parser {
  constructor(input: IToken[] = []) {
  @@ -1543,6 +1553,10 @@ function defineRecognizerSpecs(
  let parser1 = new SerializingParser([])
  const actual = parser1.getGAstProductions()
  expect(expected).to.deep.equal(actual)
  +
  + parser1.input = [createRegularToken(PlusTok)]
  + parser1.rule()
  + expect(parser1.errors).to.be.empty
  })
  it("can provide syntactic content assist suggestions", () => {
  