For Fedora 23 and 24 I simply had to update the libstdc++.so.6 symlink to use the system version of the library instead of the bundled library.

cd into your gog dir
probably
cd /home/yourUser/GOG Games/Volgarr The Viking/
cd lib

Update libstdc++ symlink to point to the version that shipped with Fedora 23/24 instead of the one that shipped from GOG.

sudo ln -sfn /usr/lib/libstdc++.so.6.0.21



When I upgraded to Fedora 25 I saw this error on ./start:

./Volgarr: symbol lookup error: /lib/libxcb-dri3.so.0: undefined symbol: xcb_send_request_with_fds

And resolved this with the following command:

In the games lib directory as above
ln -sfn /usr/lib/libxcb.so.1.1.0 libxcb.so.1.1.0

Obviously Fedora is not officially supported and these fixes 'could' in theory break anytime.
Switching libraries 'can' introduce other bugs but if you're running Fedora and trying to run GOG games on it instead of taking the easy route and running Ubuntu then you're probably fine with this risk.

I recently re-installed Fedora and downloaded a fresh copy of Volgarr. It installed but does not run.

Fedora 25 - fresh install

running ./start produces:
Running Volgarr the Viking
./Volgarr: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory

if you have this library isntalled and copy it from /usr/lib64/ to the games /lib dir and re-run start you get the following:
./Volgarr: error while loading shared libraries: libGL.so.1: wrong ELF class: ELFCLASS64
obviously because the game is expecting the 32 bit version of the library

sudo dnf provides libGL.so.1
outputs the following:

mesa-libGL-12.0.3-3.fc25.i686 : Mesa libGL runtime libraries
Repo : fedora

libglvnd-glx-1:0.2.999-14.20170308git8e6e102.fc25.i686 : GLX support for libglvnd
Repo : updates

typing sudo dnf install libGL doesn't autocomplete the library listed above.
If you type it manually...

sudo dnf install mesa-libGL-12.0.3-3.fc25.i686
Last metadata expiration check: 2:05:01 ago on Mon Jun 12 22:14:32 2017.
Error: package mesa-libGL-12.0.3-3.fc25.i686 requires mesa-libglapi(x86-32) = 12.0.3-3.fc25, but none of the providers can be installed
(try to add '--allowerasing' to command line to replace conflicting packages)

And if you add the allow erasing switch:

sudo dnf install mesa-libGL-12.0.3-3.fc25.i686 --allowerasing
Last metadata expiration check: 2:05:25 ago on Mon Jun 12 22:14:32 2017.
Dependencies resolved.
============================================================================================================== ==================================
Package Arch Version Repository Size
============================================================================================================== ==================================
Installing:
expat i686 2.2.0-1.fc25 fedora 92 k
libX11 i686 1.6.5-1.fc25 updates 623 k
libXau i686 1.0.8-6.fc24 fedora 34 k
libXdamage i686 1.1.4-8.fc24 fedora 25 k
libXext i686 1.3.3-4.fc24 fedora 43 k
libXfixes i686 5.0.3-1.fc25 fedora 22 k
libXxf86vm i686 1.1.4-3.fc24 fedora 22 k
libdrm i686 2.4.81-1.fc25 updates 162 k
libpciaccess i686 0.13.4-3.fc24 fedora 32 k
libselinux i686 2.5-13.fc25 updates 165 k
libsepol i686 2.5-10.fc25 fedora 299 k
libxcb i686 1.12-1.fc25 fedora 227 k
libxshmfence i686 1.2-3.fc24 fedora 12 k
mesa-libGL i686 12.0.3-3.fc25 fedora 173 k
mesa-libglapi i686 12.0.3-3.fc25 fedora 59 k
pcre i686 8.40-7.fc25 updates 197 k
Removing:
libglvnd-devel x86_64 1:0.2.999-14.20170308git8e6e102.fc25 @updates 0
libglvnd-glx x86_64 1:0.2.999-14.20170308git8e6e102.fc25 @updates 637 k
Downgrading:
mesa-libGL x86_64 12.0.3-3.fc25 fedora 158 k
mesa-libGL-devel x86_64 12.0.3-3.fc25 fedora 160 k
mesa-libGLES x86_64 12.0.3-3.fc25 fedora 30 k
mesa-libglapi x86_64 12.0.3-3.fc25 fedora 49 k

Transaction Summary
============================================================================================================== ==================================
Install 16 Packages
Remove 2 Packages
Downgrade 4 Packages

Total download size: 2.5 M
Is this ok [y/N]:

I suspect there's another way. I'd rather not downgrade mesa libraries that another game might require at their current version and there's no guarantee this would work anyway.

I'm guessing no one will have any suggestions since this isn't officially supported on Fedora but here's hoping.