tl;dr

libGLU.so.1 can't be accessed from within Flatpak for Heroic Launcher, but game executable can reach it when launched directly. Can't figure out how to give it access, and have never felt more like a hairless monkey in over its head.

Hi all,

Very sorry if this isn't the right place for this question, but I have been pulling my hair out yesterday and today trying to give a flatpak for Heroic Launcher access to libGLU.so.1. I am new to flatpak and Linux Mint (slowly trying to de-Microsoft), and it's mostly been smooth except for this one issue. I installed Heroic through the Mint Software Manager, linked to my GOG account and downloaded EU4 (native Linux version). There was a known issue with the Paradox Launcher and a missing symlink, which I managed, but trying to start EU4 through the launcher fails with error (./eu4: error while loading shared libraries: libGLU.so.1: cannot open shared object file: No such file or directory). When I run ldd on the executable from within the flatpak in terminal, I get libGLU.so.1 => not found. When I do it from my host, it resolves correctly (libGLU.so.1 => /lib/x86_64-linux-gnu/libGLU.so.1 (0x0000747db439c000).

I tried to add an override directly to the library, but first got an error that Path "/usr" is reserved by Flatpak. Then I tried to create a separate directory and copy the libs there and share it, which I think worked but the executable still didn't pick up the lib path. (Also, not sure it it's relevant but I think for versioning in the /usr file path, the libGLU.so.1 file is a symlink to the actual versioned file, libGLU.so.1.3.1, which is also in the same directory). Now I am trying to figure out how extensions work with Flatpak and it's not going well...

So I very clearly have no idea what I am doing, and feel like this must be a simple fix if I just knew the correct way to approach this. Any advice (including telling me that I'm insane for missing something stupidly easy), would be greatly appreciated.