# wget popcorn-6.2.1.tgz
# tar xvf popcorn-6.2.1.tgz
# cd popcorn-6.2.1
# ./configure --libs="-lbutter -lsalt"
# make -install
Please forgive errors, I don't eat popcorn anymore so my popping skills are rusty, but still better than that microwave apt-get popcorn.
It'd be better, except the OS versions of libbutter and libsalt are either too old or too new, possibly both. So you need to build them too. But to build the right version of libbutter, you will need a specific version of libcow, which they forgot to actually tag in the source code repo. First you almost try to configure libbutter with -disable-dairy to get a non-dairy version only, but then you realize that it won't be real butter, and you're not desperate enough to consider getting popcorn without real butter yet. Trying random versions from libcow source repo doesn't give success either. So, you decide to get older popcorn version 5.6 instead. But after going through the process of building libcow, libbutter and libsalt, you discover that popcorn version 5.6 has a really annoying bug for your use case. First you see if you can backport the fix, but too much has changed so the fixed code in newer version does not look anything like the broken code in 5.6, and it's not easy to see how you could just simply fix it. So, then you fall back to apt-get source popcorn, because that should have the right versions and fixes and so on. And it does, it builds and installs perfectly!
Then, while enjoying the popcorn, you suddenly realize that it's exactly the same software you would have gotten with simple apt-get install, because you didn't actually change any configure options for your "custom" build.