Black background with `gpu-api=vulkan`

mpv Information

mpv v0.40.0 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
libplacebo version: v7.349.0
FFmpeg version: 7.1.1
FFmpeg library versions:
   libavcodec      61.19.101
   libavdevice     61.3.100
   libavfilter     10.4.100
   libavformat     61.7.100
   libavutil       59.39.100
   libswresample   5.3.100
   libswscale      8.3.100

Other Information

- Linux version: Fedora Linux Asahi Remix 42
- Kernel Version: 6.15.10-402.asahi.fc42.aarch64+16k
- GPU Model:
- Mesa/GPU Driver Version: Mesa 25.2.1
- Window Manager and Version: Hyprland 0.50.0
- Source of mpv:
- Latest known working version:
- Issue started after the following happened: adding `gpu-api=vulkan`

Reproduction Steps

background=color
background-color="#ED1F1F1F"
gpu-api=vulkan
gpu-context=wayland

open mpv and see the black background color (it shows the background without gpu-api=vulkan).

Expected Behavior

A gray transparent background color

Actual Behavior

A non-transparent black background color

Log File

output.txt

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by reproducing the issue with the provided mpv configuration and compare the Vulkan and non-Vulkan behavior. Read output.txt for the rendering context details; done means gpu-api=vulkan displays the configured gray transparent background instead of opaque black.