Vim Can't Delete on MacOS

Question

I'm using vim 8.2.3017 built from source (the build version is not important since whatever version I use there exists this problem) on MacOS.

The problem in brief: I can only delete characters inserted the current insert session (each time I press i or a)

Say that I have a file test.txt already containing the word test. When I open this file by vim test.txt and try to delete any letter after pressing a or i, Mac refuses to remove the letter and sometimes produces a 'dung' sound. As a result, I can only delete characters by using x or d under normal mode.

Now I want to insert the word example, but I accidentally inserted examplw. I press delete - and then the w disappears! But when I remove the whole word example, I cannot delete more.

Then I save the file by typing :w in the command. Say that I want to delete the word example now. But I cannot delele it.

What is the problem?

Answer 1

You should probably set :h 'backspace' option:

set backspace=indent,eol,start

Where start is the one that lets you delete over start of insert pos.

Check the others in the help description.