[Error] 32-bit Vulkan fails with --nvidia when host uses split lib dirs (Fedora) and container uses merged lib (Arch)

[c4i0b]

Environment

• Host: Fedora 44, NVIDIA GeForce RTX 5080, driver 595.71.05, distrobox 1.8.2.4
• Container image: ghcr.io/ublue-os/steambox (Arch-based)
• Created with distrobox create --nvidia

When this happens

• Host with split lib dirs: Fedora / RHEL / openSUSE (/usr/lib = 32-bit, /usr/lib64 = 64-bit)
• Container with merged lib layout: Arch / Alpine (/usr/lib = 64-bit, /usr/lib32 = 32-bit, and /usr/lib64 is a symlink to /usr/lib)

When this does NOT happen

• Host and container are the same distro family (e.g. Fedora host + Fedora container)
• Container is Debian/Ubuntu based (uses x86_64-linux-gnu / i386-linux-gnu layout)
• Not using --nvidia flag

Symptoms

• 32-bit Vulkan apps fail to enumerate GPUs (VK_ERROR_INITIALIZATION_FAILED -3)
• Affects launchers that use CEF/Chromium - specifically Ubisoft Connect (The Crew Motorfest) - the window never appears
• Happens with any Proton version (Experimental, 11.0, Hotfix, GE-Proton)
• 64-bit Vulkan works fine; OpenGL works fine

Root cause
The --nvidia script does a blanket find /run/host/usr/lib* -iname "*nvidia*" and bind-mounts everything found. Since the host and container disagree on what goes in /usr/lib/:

• Host Fedora puts 32-bit libGLX_nvidia.so.0 in /usr/lib/
• Container Arch expects 64-bit libs in /usr/lib/ (merged-lib layout)
• The bind mount places the 64-bit libGLX_nvidia.so.0 (from host /usr/lib64/) into the container /usr/lib/, overwriting where the 32-bit one should be
• The 32-bit library ends up orphaned in /usr/lib32/
• The 32-bit ICD JSON (/usr/share/vulkan/icd.d/nvidia_icd.i686.json) has "library_path": "/usr/lib/libGLX_nvidia.so.0", expects 32-bit -> finds ELFCLASS64 -> fails

Workaround

nvidia-smi --query-gpu=driver_version --format=csv,noheader
ls /usr/lib32/libGLX_nvidia.so.*

Then create a corrected copy of the ICD JSON:

mkdir -p ~/.local/share/vulkan/icd.d
cat > ~/.local/share/vulkan/icd.d/nvidia_icd.i686.json << 'EOF'
{
    "file_format_version" : "1.0.1",
    "ICD": {
        "library_path": "/usr/lib32/libGLX_nvidia.so.0",
        "api_version" : "1.4.329"
    }
}
'EOF'

The api_version should match the original at /usr/share/vulkan/icd.d/nvidia_icd.i686.json. No restart needed.

Related issues

• [Error] nvidia-smi not working on Arch container, even with --nvidia flag #2085 - Same root cause affecting 64-bit tools (nvidia-smi) on Arch containers with --nvidia
• [Error] Vulkan Nvidia ICD files missing (Bazzite) #1843 - Previous Vulkan ICD issue, fixed by PR [#1687] Fixes Vulkan ICD config files for NVIDIA driver host integration (openSUSE, Fedora) #1688 (ICD naming convention update)
• PR fix: nvidia library resolution on merged-lib guests (e.g. Arch) #2014 - Attempted fix for merged-lib library resolution (still open)

[c4i0b]

Simpler workaround: skip --nvidia, let pacman handle it

If you use an Arch-based image on an Arch host (merged libs), --nvidia corrupts /usr/lib32/ by bind-mounting 64-bit ELFs there (see root cause above). The fix:

1. Create the container without --nvidia
2. Install nvidia-utils + lib32-nvidia-utils via pacman
3. Or install Steam and select lib32-nvidia-utils as the lib32-vulkan-driver provider

No workaround needed post-creation. This works because lib32-nvidia-utils installs genuine 32-bit ELF libraries from the Arch repos, matching your host driver version.

Bottom line: --nvidia is not needed on Arch-based containers. Just pacman-install the NVIDIA packages.

[c4i0b]

TL;DR: --nvidia is fundamentally broken on any guest when the host uses merged-usr (e.g., Arch). The 64-bit host /usr/lib is bind-mounted into the guest's 32-bit lib path, corrupting the multilib layout.

Tested across Arch and Fedora guest containers on an Arch host:

Arch guest:

• --nvidia breaks gaming entirely — 64-bit ELFs land in /usr/lib32/ where 32-bit is expected.
• Workaround: create without --nvidia, install nvidia-utils + lib32-nvidia-utils via pacman inside the container.

Fedora guest:

• --nvidia partially works: 64-bit gaming runs fine (libs resolve from /usr/lib64/), but the 32-bit lib path (/usr/lib/) is populated with 64-bit ELFs from the host's merged /usr/lib/.
• This causes Steam's built-in performance overlay (and likely any 32-bit tooling) to show 0% GPU usage — it can't find genuine 32-bit NVIDIA libraries.
• The host's 32-bit libs (/usr/lib32/) are not mounted anywhere in the container.
• No clean workaround yet — the bind-mounts from --nvidia conflict with installing proper 32-bit packages via dnf.

Root cause: --nvidia assumes the host's /usr/lib layout matches the guest's, but merged-usr hosts (Arch, Ubuntu 24.04+) put 64-bit libs in /usr/lib, while split-lib guests (Fedora) expect 32-bit there.