Async functions emit Rollup warning `this has been rewritten to undefined` -- can't repro

When I try to build a file containing async functions, there’s the following warning:

this has been rewritten to undefined

Environment

• node v10.16.0
• rollup-plugin-node-resolve (^5.2.0)
• rollup-plugin-typescript2 (^0.24.2)
• rollup-plugin-babel (^4.3.3)
• rollup-plugin-commonjs (^10.1.0)
• rollup-plugin-terser (^5.1.2)

Versions

• typescript: ^3.6.3
• rollup: ^1.21.4
• rollup-plugin-typescript2: ^0.24.2

rollup.config.js

import resolve from 'rollup-plugin-node-resolve'
import typescript from 'rollup-plugin-typescript2'
import babel from 'rollup-plugin-babel'
import commonjs from 'rollup-plugin-commonjs'
import { terser } from 'rollup-plugin-terser'

import pkg from './package.json'

const extensions = ['.js', '.jsx', '.ts', '.tsx']

export default {
  input: ['src/index.ts'],
  output: {
    file: pkg.main,
    format: 'cjs'
  },
  external: ['@slack/client', 'dlv', 'dotenv', 'googleapis', 'micro'],
  plugins: [
    resolve({ extensions }),
    typescript({
      useTsconfigDeclarationDir: true
    }),
    babel(),
    commonjs(),
    terser()
  ]
}

tsconfig.json

{
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "moduleResolution": "node",
    "target": "es2015",
    "module": "es2015",
    "resolveJsonModule": true,
    "esModuleInterop": true,
    "declaration": true
  },
  "include": ["src/**/*.ts"],
  "types": ["node"]
}

[bastienrobert]

Alright, I think I’m just going crazy. The error has disappeared, I can not re-create it. Well… so i’m closing this 🤷🏻‍♂️ Sorry for making you waste time @ezolenko

[ezolenko]

I think this is a problem with your code, read the description at that rollup link: https://rollupjs.org/guide/en/#error-this-is-undefined