I maintain a huge number of git mirror of git repositories and i have some overview of activity there. Many open source projects have stopped activity and/or do not make any new releases. Like syslinux, which seems to be in a similar situation as unzip. And some projects like Quagga went completely awol and don't even have a functional git remote.
So unzip is not really that special, its a mode general problem with waning interest.
I wasn't trying to imply that unzip is the only one.
But the way I learned that unzip is unmaintained was pretty horrible. I found an old zip file I created ages ago on Windows. Extracting it on Arch caused no problem. But on FreeBSD, filenames containing non-ASCII characters were not decoded correctly. Well, they probably use different projects for unzip, this happens. Wrong, they use the same upstream, but each decided to apply different patches to add features. And some of the patches address nasty bugs.
For something as basic as unzip, my experience as a user is that when it has so many issues, it either gets removed completely or it gets forked. The most reliable way I found to unzip a zip archive consists of a few lines of python.
I agree completely. I also know that distros patch packages.
But for unzip the situation is particularly bad because it has no maintainer. Normally, you would raise feature requests for basic functionality upstream and once added, the maintainer would cut a new release. So software with the same version number generally, but not always, behaves similarly across distros.
But for unzip, because upstream is unmaintained, distro maintainers started to add features while keeping the version number. So in the end you end up with different behavior for what looks like the same release.
So unzip is not really that special, its a mode general problem with waning interest.