ERROR: ld.so: object '/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/var/home/mathieub/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/var/home/mathieub/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
ERROR: ld.so: object '/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/var/home/mathieub/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/var/home/mathieub/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/run/host/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/run/host/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/run/host/usr/lib/extest/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ProtonFixes[15683] WARN: [CONFIG]: Parent directory "/home/mathieub/.config/protonfixes" does not exist. Abort.
Proton: Upgrading prefix from None to GE-Proton10-15 (/run/media/mathieub/HDDGames/SteamLibrary/steamapps/compatdata/1903340/)
Traceback (most recent call last):
  File "/var/home/mathieub/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/proton", line 2188, in <module>
    g_session.init_session(sys.argv[1] != "runinprefix")
  File "/var/home/mathieub/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/proton", line 2036, in init_session
    g_compatdata.setup_prefix()
  File "/var/home/mathieub/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/proton", line 1059, in setup_prefix
    os.symlink("../drive_c", self.prefix_dir + "/dosdevices/c:")
OSError: [Errno 22] Invalid argument: '../drive_c' -> '/run/media/mathieub/HDDGames/SteamLibrary/steamapps/compatdata/1903340/pfx//dosdevices/c:'