Some python library packages (e.g. python-configobj) come with API
documentation processed by epydoc.  Typcially they ship with a copy of
the required javascript in the file epydoc.js somewhere among the html
documentation.

When I browse any of the html files created from python source [1] and
click on one of the (black, underlined) hot symbols, a tooltip-like
miniature window pops up with a disambiguation menu.  But the moment I
move the mouse (trying to click on one of the disambiguated items) the
tooltip disappears - and worse, _the original linked symbol_ disappears
with it, corrupting the source display.

[1] example:
file:///usr/share/doc/python-configobj/api/configobj-pysrc.html#Builder.build_Dict

src:iceweasel has been superseded by src:firefox-esr in version
45.0esr-1 in March 2016. Transitional packages to ease upgrades were
provided in the wheezy, jessie, stretch and buster releases. The
transitional packages have been removed finally before the bullseye
release in August 2021.
After regular security support for buster ended in August 2022 and LTS
support ended in June 2024, I'm closing the remaining bug reports now.

Andreas