git.fetch documentation code example crashes

When trying to run the code block on the git.fetch documentation webpage, I get the following error (happens in both Chrome and Firefox):

name: "TypeError"
message: "Cannot read property 'split' of null"
stack: "TypeError: Cannot read property 'split' of null
    at new b (https://unpkg.com/isomorphic-git@0.55.2/dist/bundle.umd.min.js:8:64118)
    at Function.from (https://unpkg.com/isomorphic-git@0.55.2/dist/bundle.umd.min.js:8:64353)
    at https://unpkg.com/isomorphic-git@0.55.2/dist/bundle.umd.min.js:8:28034
    at Generator.next (<anonymous>)
    at o (https://unpkg.com/isomorphic-git@0.55.2/dist/bundle.umd.min.js:8:27621)
    at s (https://unpkg.com/isomorphic-git@0.55.2/dist/bundle.umd.min.js:8:27823)"
fileName: undefined
lineNumber: undefined
columnNumber: undefined

I get the same error when trying to run git.fetch in the browser with my own project.

As a side note: is using git.fetch the recommended way of retrieving the commits of a large repository (large == many commits) in a paginated way, when the end goal is to compare files between adjacent commits in an efficient way?

[jcubic]

I think that you can’t just fetch the commits, you need to have git repository to do this, so you first need to clone the repo, or create new one and add remote and then fetch (not sure about the last one).

[kpj]

I think that neither .git/config nor .git/ exist, because I am trying fetch commits from a remote repository which does not exist locally. This is the relevant code:

import FS from '@isomorphic-git/lightning-fs'
const git = require('isomorphic-git')

const fs = new FS('fs', { wipe: true })
git.plugins.set('fs', fs)
const pfs = fs.promises

const dir = '/repo'
await pfs.mkdir(dir)

const res = await git.fetch({
  dir: dir,
  corsProxy: 'https://cors.isomorphic-git.org',
  url: repoUrl,
  ref: branch,
  singleBranch: true,

  depth: 1
})