CIDER's browse-ns functionality just got reworked in a major way https://github.com/clojure-emacs/cider/pull/3217

(the name of the PR is a bit misleading)

@bozhidar Thank you for cider! I had a lazy-seq getting realized and did not know where it got called from. Putting a #break before a function it called and I can press c continue to the next call or press s to get a nice stack-trace to see where it gets called from. Nice!!! Just needed once every two years but boy is it nice to have it be there when I do need it!!!!

Better late than never. 😉