When selecting »Package Tracking System« on
https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=Dpkg;dist=unstable I
get a »404 File not found« (and no, Dpkg does still exist ;-)). The
link is to http://packages.qa.debian.org/Dpkg while the correct link
uses a lower case »d«, i.e. http://packages.qa.debian.org/dpkg

While this is true and perhaps debbugs should force that to lower case
in more places (displaying the maintainer also doesn't work, for
instance), isn't the problem that you visited pkg=Dpkg in the first
place rather than pkg=dpkg?  How did you end up at the first link?

Hello Colin,
links bugs.debian.org/Dpkg
in the console. Which worked, except that the link to the package page
no longer works.

Greetings

            Helge

Right, so debbugs does case-insensitive comparisons internally but
doesn't force to lower-case for external links.  I think it's always
been that way.  Visiting http://bugs.debian.org/dpkg will of course
behave more sensibly.