Error when doing bench update

When doing bench update when the new version coming up the following message came

Merge the frappe app manually with "git pull" / "git pull --rebase" and fix conflicts.
Temporarily remove your changes with "git stash" or discard them completely
with "bench update --reset" or for individual repositories "git reset --hard"
If your changes are helpful for others, send in a pull request via GitHub and
wait for them to be merged in the core.

I reviewed different topics, and they suggested doing the following:
1.Go to the directory, either frappe-bench/apps/erpnext or frappe-bench/apps/frappe
2.Type git status
3.Check the list of the untracked files. There might be files, which do or don’t belong there.
4.Type git add --all to track those files
5.Type git stash
6.Run bench update
7.It should run successfully, if not, start over with 1. and repeat for the other directory

when I’m doing the above steps I found the problem located in the file init.py existed under /bench/erpnext/apps/frappe/frappe/www/_test/assets
by the way, the init.py file is empty when I reviewed it

I have tried again doing bench update --reset as recommended too, but the same issue came to me the error come after bench update is again:

Cannot proceed with update: You have local changes in app "frappe" that are not committed.

Here are your choices:
    Merge the frappe app manually with "git pull" / "git pull --rebase" and fix conflicts.
    Temporarily remove your changes with "git stash" or discard them completely
    with "bench update --reset" or for individual repositries "git reset --hard"
    If your changes are helpful for others, send in a pull request via GitHub and
    wait for them to be merged in the core.

Well I had the same problem and did the same thing and it resolved the issue.
Did you try git reset --hard?

No I didn’t

It is added as a bug
https://github.com/frappe/bench/issues/1225