/usr/lib/x86_64-linux-gnu/wine-development/libd3d12.def is in libwine-development-dev 3.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | ; File generated automatically from dlls/d3d12/d3d12.spec; do not edit!
LIBRARY d3d12.dll
EXPORTS
D3D12CreateDevice @101
D3D12GetDebugInterface @102
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