Why is “set autoindent” in my ~/.vimrc ignored when I open a file?

Question

I have set autoindentation, but vim somehow ignores it because :set autoindent? says noautoindent however the last file to have set autoindent is really my vimrc file according to :verbose set autoindent?

noautoindent
        Last set from ~/myScripts/.vim/vimrc line 10

However set autoindent is really in my vimrc file :

$ grep -n autoindent ~/myScripts/.vim/vimrc
10:set autoindent

EDIT0 : Lines between 9 and 11 of my ~/myScripts/.vim/vimrc file :

$ sed -n 9,11p ~/myScripts/.vim/vimrc
set nohls
set autoindent
set noexpandtab tabstop=4 shiftwidth=4

EDIT1 : ~/.vim/vimrc is pointing to my ~/myScripts/.vim/vimrc :

$ readlink -f ~/.vim/vimrc
/home/sebastien/myScripts/.vim/vimrc

EDIT2: Thanks to filbranden, it seems that paste and autoindent are mutually exclusive :

The 'autoindent' option is reset when the 'paste' option is set and restored when 'paste' is reset.

Here's what I had in my ~/myScripts/.vim/vimrc :

$ egrep -n "^set ((no)?autoindent|(no)?paste)" ~/myScripts/.vim/vimrc
10:set autoindent
67:set paste

Answer 1

This is happening due to :set paste.

As :help 'autoindent' says:

The 'autoindent' option is reset when the 'paste' option is set and restored when 'paste' is reset.

It turns out this affects the way :set ai? reports the setting, even though :verbose still keeps showing the source for the setting coming from the same line:

:verbose set ai?
  autoindent
    Last set from ~/.vim/plugged/vim-sensible/plugin/sensible.vim line 20
:set paste
:verbose set ai?
noautoindent
    Last set from ~/.vim/plugged/vim-sensible/plugin/sensible.vim line 20

So just make sure you don't have 'paste' enabled. It shouldn't be enabled during normal operation anyways...

---

If you want a helper to manage enabling 'paste' when you're pasting external text into Vim, I recommend vim-unimpaired which defines a yop mapping (together with [op and ]op). From :help yop:

A toggle has not been provided for 'paste' because the typical use case of wrapping of a solitary insertion is inefficient: You toggle twice, but you only paste once (YOPO). Instead, press [op, ]op, or yop to invoke O, o, or 0C with 'paste' already set. Leaving insert mode sets 'nopaste' automatically.