Some Kind of Build Setting

I wrote a whole bunch of stuff for a different question, then did a quick check, and realized that my question is quite different, so I deleted all that and ask this question:

Something changed. I don't know when, but it's super annoying. On the Configuration Manager, there is a checkbox for Build. Having that not checked means that you can select Build, Rebuild, or do anything else you can think of. The project doesn't build without that checked. You don't get a message about it. The small progress graphic in the lower left of VS will show the same progress, but nothing is happening. The project simply doesn't build.

I have no idea why that checkbox even exists. It may have something to do with the Deploy checkbox beside it, but I don't know. Why is that even there? If you select Build, you expect the thing to...wait for it...BUILD!!! But if you don't have that checkbox checked, what you get is NOTHING!

It's probably for that reason that the Build checkbox is checked by default, such that when the user selects build, something actually builds, rather than VS just showing you graphics and doing nothing at all.

At some point in the not very distant past (though perhaps when I moved to VS2019), that checkbox got cleared on a whole bunch of my projects. I only found out about it because I had a few projects that simply wouldn't do anything when I built them. They wouldn't even create the output folders if those weren't present, or they'd appear to work, only to then clearly be referencing things that went out of date years back. So, now I get to go through all the projects and see whether that foolish checkbox is checked for both the debug and release builds for every one of some 30 projects (it wasn't cleared for all builds of all projects).

Can somebody shed some light on this? What is that checkbox for? Why are you even allowed to build and have it quietly NOT build...but act like it was? How could it have gotten cleared? Can you lock that option so that it doesn't magically flip, the way it did for me? Is there some kind of option setting that states, "build means actually BUILD, not do nothing."?

A solid sample showed that the debug checkbox only got unchecked for a critical few projects. How could that happen, and why the checkbox exists, are still valid questions.

I don't know how the box could get unchecked without you unchecking it, other than manually editing the file that that dialogue exposes, but the box is there so that you can exclude certain projects from the build of the solution. Generally you're going to want all projects in a solution to build but you may want to exclude some projects is certain configurations.

Ah, that makes sense. I've always written one project per solution, solutions, so I've never encountered a case where I might optionally not build some part of it.

I never went into Configuration Manager until I started looking for a cause for the bizarre behavior I was seeing. For that reason, I'm pretty sure I never unchecked that box. A set of projects had the box unchecked, but not ALL of the 35 or so that are parts of the overall project (running out of synonyms, here). Only perhaps about 5 appear to have gotten unchecked. Those five don't seem quite random, either. The project consists of some core models, a main program, and a bunch of plugins which can be quite trivial in size and complexity. The 5 that got the box unchecked were all core models and one very important plugin. On the one hand, those are elements I'd be more likely to visit, so they'd be more likely to change, but on the other hand...I never go into Configuration Manager, so there's that.

In fact, what prompted me to start this thread was that I was studying an issue where a plugin appeared to be depending on a class that I refactored out of the design years ago. I'm not sure how many years ago, but at least three. So, that's how out of date the debug version of the plugin was. It didn't get built because the box was checked for the release build, but unchecked for the debug build, so the debug build was years out of date.

Very odd. Just a glitch of some sort, I suppose.