Subnautica: Below Zero (848450)

Compatibility Report

• Name of the game with compatibility issues: Subnautica: Below Zero
• Steam AppID of the game: 848450

System Information

• GPU: [AMD/ATI] Tahiti XT [Radeon HD 7970/8970 OEM / R9 280X] [1002:6798]
• Driver/LLVM version: mesa-vulkan-drivers-19.0.0-0.8.git.a920979d4f3.fc29.x86_64, xorg-x11-drv-amdgpu-18.1.99-0.16.git9045fb3.fc29.x86_64 (amdgpu, radv)
• Kernel version: 4.20.4
• Link to full system information report as Gist: steam-system-info-2019.01.31.txt
• Proton version: 3.16-6 Beta

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Symptoms

Game does not start at all when trying to launch from Steam.

Reproduction

Try to launch Subnautica: Below Zero from Steam.

Steam log and circumvention for this issue

When trying to launch the game from Steam, following appears on terminal:

>>> Adding process 5841 for game ID 848450
Traceback (most recent call last):
  File "/home/im/.local/share/Steam/steamapps/common/Proton 3.16 Beta/proton", line 309, in <module>
    shutil.copy(basedir + "/dist/lib/wine/dxvk/openvr_api_dxvk.dll", prefix + "/drive_c/windows/syswow64/")
  File "/usr/lib64/python3.7/shutil.py", line 245, in copy
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/usr/lib64/python3.7/shutil.py", line 121, in copyfile
    with open(dst, 'wb') as fdst:
IsADirectoryError: [Errno 21] Is a directory: '/home/im/.local/share/Steam/steamapps/compatdata/848450/pfx//drive_c/windows/syswow64/'
Game removed: AppID 848450 "", ProcID 5840 
JS method call SharedConnection.SendMsgAndAwaitResponse with 3 arguments

After creating the mentioned directory manually (mkdir ~/.local/share/Steam/steamapps/compatdata/848450/pfx//drive_c/windows/syswow64/), it proceeds a bit further:

>>> Adding process 9888 for game ID 848450
Traceback (most recent call last):
  File "/home/im/.local/share/Steam/steamapps/common/Proton 3.16 Beta/proton", line 310, in <module>
    shutil.copy(basedir + "/dist/lib64/wine/dxvk/openvr_api_dxvk.dll", prefix + "/drive_c/windows/system32/")
  File "/usr/lib64/python3.7/shutil.py", line 245, in copy
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/usr/lib64/python3.7/shutil.py", line 121, in copyfile
    with open(dst, 'wb') as fdst:
IsADirectoryError: [Errno 21] Is a directory: '/home/im/.local/share/Steam/steamapps/compatdata/848450/pfx//drive_c/windows/system32/'
Game removed: AppID 848450 "", ProcID 9887 

After creating another directory (mkdir ~/.local/share/Steam/steamapps/compatdata/848450/pfx//drive_c/windows/system32/), game starts normally and becomes playable.

Start with the Proton 3.16 Beta proton script around lines 309-310, where the traceback shows the two shutil.copy calls failing. Reproduce the launch with AppID 848450 and inspect how the destination paths are handled. Done means the game launches without manually creating the syswow64 and system32 directories.