Dear Maintainer,
the short version:
$ dpkg --search /usr//bin/dpkg
dpkg-query: no path found matching pattern /usr//bin/dpkg
$ dpkg --search /usr/bin/dpkg
dpkg: /usr/bin/dpkg
Full story: Either mandated by POSIX or at least common practise for a
very long time: It doesn't matter if there's just one slash in a
filename specification, or more than that. As seen above however,
dpkg --search does not follow that concept, which is a bit surprising.
So, for robustness, please implement a relaxed lookup.
Christoph