You can search for identifiers within the package.
in-package search v0.2.0
thread_.ml
1 2 # 1 "src/subscriber/thread_.real.ml" let[@inline] get_tid () = Thread.id @@ Thread.self ()
1 2
# 1 "src/subscriber/thread_.real.ml" let[@inline] get_tid () = Thread.id @@ Thread.self ()