helm-swoop no longer works for me. Whenever I try to use it, i get the message
Symbol's value as variable is void: helm-swoop-pattern
I am using the latest package from MELPA (20170923.2127) which has not been updated since September. So I have no idea what has caused this issue to suddenly crop up.
I am using Emacs 25.3 on macOS. I do not have any helm-swoop specific config in my init.el and am using it "plain-vanilla".
This has now been fixed and merged. https://github.com/ShingoFukuyama/helm-swoop/pull/125
I just updated helm-swoop to version 20180215.354 from MELPA. This version contains the fix and the problem is indeed gone.
This is a known issue caused by a breaking change in Helm: https://github.com/ShingoFukuyama/helm-swoop/issues/123.
Feel free to manually apply a fix from https://github.com/ShingoFukuyama/helm-swoop/pull/124.
Given that the maintainer of helm-swoop seems to have abandoned the package, I switched to swiper-helm. It also offers multi-buffer search based on helm and it's better maintained.
