ZDoom

I have Shadow Warrior Classic Complete on GOG.com, and the Linux installer puts the Twin Dragon files into the "dragon" subdirectory of the main game data directory. When I run Raze from the main game data directory, it sometimes loads Sw.grp from the "dragon" subdirectory, even if I don't want it to do so.

Reminds me of this one: viewtopic.php?f=341&t=72115

These packages surely come without any consideration for how to set up their data.
I'm afraid, but I do not have a quick solution here, it may be best to move that folder elsewhere if it causes interference.

Hmm, this happens with Duke Nukem 3D Megaton Edition from Steam as well; The duke3d.grp inside the "classic" folder is randomly loaded instead of the one in the working directory.

Irrespective of it loading SW.grp fom the Twin Dragon folder, it is actually a problem as such? The only main issue I see here is content in Raze's directory should always override a search path, unless the search path is higher than Raze's path listing for $PROGDIR in your INI file.

I've never had this happen when I was still using my GOG installation of SW.
Is this something exclusive to Linux?
I can't do anything here as I cannot reproduce this.
In any case, I'd strongly recommend not to run these games from those dirty installations - it's really better to copy the GRPs to some safer location because it massively reduces the risk of loading unwanted garbage content.