Powerline: Powerline bar disappears when sourcing .vimrc and leaves me with a plain statusline

You have to remove your set statusline statements from your vimrc.

All 'set statusline' statements in my rc file got commented out, leaving the line containing 'set laststatus=2'. Still the problem persists. Please don't close the bug rapport until the suggested fix is verified.

I can see that you're using an old version of Powerline since the python from powerline.bindings.vim import source_plugin; source_plugin() statement has been changed to updating the runtimepath instead in recent versions. Please update to the latest revision and update your vimrc according to the docs and let me know if the error still persists.

OK. Updated powerline and changed the powerline invocation statement in my rc file.

This helped in the case where I manually source my .vimrc file within vim, but I have an autocmd command that sources the .vimrc file everytime the rc file is saved. When I saved my rc file, causing the command on line 232 in my .vimrc, I get bug #153

When using autocmd that resources your vimrc _always use autocmd-nested_.

@Lokaltog I guess this information should be added to troubleshooting as it is common to have autocmd that resources vimrc on save, and I already saw at least one same question on SO. Most of the time ColorScheme event is the only one actually used event that may be launched on resourcing vimrc (SourcePre and SourceCmd are also omitted without nesting, but I almost never see them used; except for SourceCmd commands for {proto}:// pseudo-protocols and (possibly compressed) vimball files).

@ZyX-I Thanks, I'll add it to the troubleshooting.