What situations call for source code packages?
 

I know from research that the debate over source vs binary is close, with maybe source edging out binary a tiny bit. I would like to know what situations would source code definitely be the way to go. I know this is a very generic question but I guess I'm just looking for some generic answers! Thanks in advance!

Why don't you cite the research which supports your first statement?

The only time I know of that source beats binary is when a security patch is supplied (or the source has been patched) in source before the binaries from a distribution are ready; AND there is an ongoing threat.

It was this reason I used to automatically rebuild sendmail, bind, ssh, ntp, and a few other tools, from source. At the time I was supporting IRIX, Solaris, and Linux systems. These projects tended to have security fixes provided faster than the official corporate repositories would have them.

The downside is that you have to accept the responsibility for final/production testing.
It allowed me to pass a number of security audits where others would fail. We called it "proactive support". Where source wasn't available (Some Solaris/Irix systems and tools, and no mitigation known) we would still fail.

The only OTHER situation is where the tool/utility didn't work properly, but where the latest source would (SAMBA fit this a couple of years ago, the performance of the available binary sucked, but the latest updates fixed that, so we replaced the binary with a locally compiled source).

The downside is that you have to accept the responsibility for production testing.

There are things that, yes, you can build it yourself from source but, no, you probably don't need to do that.

For example: Oracle Java, Oracle VirtualBox, Apache OpenOffice, The Document Foundation LibreOffice are all open source but are also all available as "installable" packages.

Similarly, Mozilla Firefox, Thunderbird and SeaMonkey (all of which can be built from source).

Thing is, if you're a purist you will take the time and trouble to download the source, read the build instructions and have at it. If the build is successful, installs and works, there you go.

You will spend hours doing so and, essentially, you're just watching compilation fly by on the screen.

On the other hand, there are any number (probably in the millions) of packages, utilities, tools, whatever that are only available as source and almost always come with a configure-make-make install method for building -- there is nothing whatsoever wrong with building from source in those cases and you'll have a piece of software that you would not otherwise have access to. You may, in some cases, need to install required packages before you can build the one you really want (and they'll most likely be configure-make-make install too). You can build an entire Linux system from source if you want to (might take a while, that).

You may want or need to enable an option in a ready-built package and, having the source, you can do that.

It's really a balance between availability and time (yours). I build from source, I download and install already-built package software.

It's pretty much up to you.

Hope this helps some.