@JimLynchCodes, СС @tschaub

This logic already exists, but it's a little bit broken.

Git.prototype.checkout = function(remote, branch) {
  const treeish = remote + '/' + branch;
  return this.exec('ls-remote', '--exit-code', '.', treeish).then(
    () => {
      // branch exists on remote, hard reset
      return this.exec('checkout', branch)
        .then(() => this.clean())
        .then(() => this.reset(remote, branch));
    },
    error => {
      if (error instanceof ProcessError && error.code === 2) {
        // branch doesn't exist, create an orphan
        return this.exec('checkout', '--orphan', branch);
      } else {
        // unhandled error
        throw error;
      }
    }
  );
};

git ls-remote checks that target remote branch exists by treeish pattern. Once it throws exit code 2, git checkout --orphan gh-pages is called to create a new one.

Mentioned error is related to return this.exec('checkout', branch) invocation, and it throws 1 which does not match to error.code === 2 condition. Probably your repository has a ref (tag / local branch) that satisfy treeish.

I deleted the entire gh-pages branch.

@JimLynchCodes - do you recall what you did to delete the branch? Something like git push --delete origin gh-pages? Or git branch -D gh-pages? Or something else?

@JimLynchCodes - do you recall what you did to delete the branch?

I had the same issue and used git push origin --delete gh-pages to delete the branch

Related to #17 ?