Sleuth enables "filetype indent" unconditionally

[dbarnett]

If you have sleuth.vim installed, you will always have filetype indent enabled when plugin/sleuth.vim loads.

It may seem obvious that enabling an indentation-related plugin would enable extra indent settings on you, but since it loads after vimrc time and there's no :verbose filetype variant to troubleshoot what's overriding :filetype on you, it's pretty painful tracking down why you're not able to disable filetype indent from your vimrc if you decide to try it.

[sheerun]

vim-polyglot doesn't set filetype indent and it's up to user to set it (usually it's on by default)

[tpope]

My intent was that let g:did_indent_on = 0 could be abused to opt out of this, but you make a good point about discoverability, so I'm adding a documented option.

usually it's on by default

It's off by default on Debian based distros. That alone is a big enough exception that I think it's worth Sleuth taking responsibility for this.