Gentoo user…but assuming now it’s about building on distributions that don’t automate it like gentoo.

Disadvantages:

• No easy way to uninstall again. Some build systems generate lists of files that were installed or even some uninstall rules but that requires to either keep the build directory with the source-code around or to make backups of the necessary build files for proper uninstall. And in some build systems there are no helpers for uninstalling at all.
• Similar…updating doesn’t guarantee to remove all traces of the previous version. If the new build overwrites every file of the previous version…fine. But if an update version doesn’t need files anymore that were installed in previous versions those will usually not get remove from your system and stick around.
• In general lack of automatism for updates
• Compiling takes time
• You are responsible for dealing with ABI breakages in dependencies. In most cases the source-code you compile will depend on other libraries. Either those come from your distro or you also build them from source…but in both cases you are responsible for rebuilding a package if an update to one of the dependencies breaks the ABI.
• You need build-time dependencies and depending on your distro also -devel packages installed. If source-code you install needs an assembler to build you have to install that assembler which wouldn’t be necessary if you installed the binary (You can remove those build-dependencies again of course until you need to rebuild). Similar for -devel packages for libraries from your distro…if the source-code depends on a library coming from your distro it also needs the header files, pkgconfig files and other development relevant files of that library installed which many distros split out in own -devel packages and that aren’t necessary for binaries.
• You have to deal with compile flags and settings. It’s up to you to set the optimization level, architecture and similar for your compiler in environment variables. Not a big deal but still something someone has to look into at the start.
• You have to deal with compile-time options and dependencies. The build-systems might tell you what packages are missing but you have to “translate” their errors into what to install with your package manager and do it yourself. Same for the detection of the build systems…you have to read the logs and possibly reconfigure source-code after installing some dependencies if he build systems turned off features you want because of lacking dependencies.
• Source-code and building need disk space so make sure you have enough free. Similar with RAM…gentoo suggests 2GB of ram for each --job of make/ninja but that’s for extreme cases, you usually can get away with less than 2GB per job.

Of course you also gain a lot of advantages…but that wasn’t asked ;)

You can “escape” most of the mentioned disadvantages by using a distro like gentoo that automates much of this. It’s probably worth a look if you plan on doing this regularly.

edit:typos

Yep, I really don’t understand why people use baloo without content indexing…if you do that other means like your fd or even mlocate will probably be better solutions if all you need is filename search. KDE integration is really the only advantage left then…and I don’t really see much need of creating bookmarks/folderviews with filename searches, you hardly ever have reoccurring searches for the same filenames.

Baloo only makes sense to use with content indexing in my view…and there it hardly has any equal. I personally can’t be without this feature anymore. I use it actively since KDE4 days (anyone remembering nepomuk?) and my whole workflow is built on it.

For me the real advantages of baloo are metadata search and KDE integration.

Searching for tags with baloosearch6 tag:<tag> is something I use rather often, I even use the star ratings in baloosearches with rating>=6. Combine that with a mimetype and and you have a quick playlist of all music you rated with 4 or more stars in dolphin: baloosearch rating>=8 AND type:audio.

I also using baloosearch for images…the width and height keys are really useful for finding textures with specific dimension…something like baloosearch type:image AND Width>=2048 AND Height>=2048

And the of course the KDE integration that makes this really useful…you can use baloosearch queries everywhere in KDE, in open-file dialogs, as bookmarks in dolphin or file-dialogs, for desktop widgets showing folders…you can easily create an activity that has several folder-views on the desktop each showing a different set of files with specific tag…so left folder-view showing all files tagged “WIP” while right folder-view shows all files tagged “Finished” (To use queries in KDE you need them in the form baloosearch:/?querry=<the querry as you would use it in balooserarch6>

Edit:I wrote a reddit post some years ago about this…hope linking reddit is okay here: https://www.reddit.com/r/kde/comments/pmcshj/tip_baloosearch_kioslave/