nvim --headless segfaults if you poke it
The recommended way plenary has for running tests (e.g. nvim --headless --noplugin -u scripts/minimal_init.vim -c "PlenaryBustedDirectory lua/tests/ { minimal_init = './scripts/minimal_init.vim' }") makes it easy I think to run into neovim/neovim#12432 or neovim/neovim#11362 (which I ran into randomly just now after having used plenary for a day or two).
The fix in one of those two issues (to add set display=lastline) helped stop the segfaulting and showed me my real error, but might be good to add a recommendation to include that in minimal vimrcs to the docs.
@Julian Is there a reason why you did not create a PR yet to minimal.vim ?
Issue 11362 sounds like it requires logging or tracing.
What are you referring to by minimal.vim? The thing here in the scripts dir? That wouldn't have helped me, I don't use that when running tests with plenary, I have my own minimal vimrc. I don't think the docs even mention that file, but I don't recall.
Yes, https://github.com/nvim-lua/plenary.nvim/blob/master/tests/minimal_init.vim You can add it as comment, since that is the place everybody will look to adapt their minimal vimrc.