set expandtab in .vimrc not taking effect

Question

For some reason the set expandtab command in my .vimrc file is not having any effect.

Here is my .vimrc:

" tab settings
set expandtab
set smarttab
set softtabstop=2
set tabstop=2
set shiftwidth=2
set paste

However, when I run vi (no file name) the :set command emits:

:set
--- Options ---
  helplang=en         shiftwidth=2        ttyfast
  paste               tabstop=2           ttymouse=xterm2
  fileencodings=ucs-bom,utf-8,default,latin1

which indicates that the expandtab option is not set. This is further confirmed by executing :set expandtab? which returns with noexpandtab.

I'm on OSX 10.10, and vi --help returns:

$ vi --version
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Jun 20 2016 11:11:25)
MacOS X (unix) version
Included patches: 1-1847
Compiled by Homebrew

How come some settings in my .vimrc are being honored, but not set expandtab?

Answer 1

From the documentation on expandtab:

This option is reset when the paste option is set and restored when the paste option is reset.

BTW, you probably don't want paste to be set all the time. It's commonly used for pasting into a terminal Vim to avoid messing up indentation, etc.

To conveniently turn paste on and off with one keypress you can add this shortcut (change <F2> to whatever key you want):

set pastetoggle=<F2>