Cloning a tag-named branch introduced a supply chain attack vector,
because branch and tag contents might differ.
Now the hashed worktree always corresponds to the tag that is GPG-verified.
qemu_kvm is only built for one architecture, so it's smaller and takes
MUCH less time to build if it has to be built from source. And this
module doesn't support running a VM for one architecture from another
architecture, so the one architecture is all we'll need.
Some upstream changes broke the automatic fallback to SwiftShader.
Without this workaround the GPU initialization fails (apparently due to requiring Vulkan):
machine # libva error: vaGetDriverNameByIndex() failed with unknown libva error, driver_name = (null)
machine # [1001:1001:1101/104304.000625:ERROR:viz_main_impl.cc(161)] Exiting GPU process due to errors during initialization
machine # libva error: vaGetDriverNameByIndex() failed with unknown libva error, driver_name = (null)
machine # [1052:1052:1101/104305.060496:ERROR:viz_main_impl.cc(161)] Exiting GPU process due to errors during initialization
machine # [1084:1084:1101/104305.165898:ERROR:angle_platform_impl.cc(44)] Display.cpp:894 (initialize): ANGLE Display::initialize error 0: Internal Vulkan error (-3): Initialization of an object could not be completed for implementation-specific reasons, in ../../third_party/angle/src/libANGLE/renderer/vulkan/RendererVk.cpp, initialize:1048.
machine # [1084:1084:1101/104305.171191:ERROR:gl_surface_egl.cc(782)] EGL Driver message (Critical) eglInitialize: Internal Vulkan error (-3): Initialization of an object could not be completed for implementation-specific reasons, in ../../third_party/angle/src/libANGLE/renderer/vulkan/RendererVk.cpp, initialize:1048.
machine # [1084:1084:1101/104305.178707:ERROR:gl_surface_egl.cc(1382)] eglInitialize SwANGLE failed with error EGL_NOT_INITIALIZED
machine # [1084:1084:1101/104305.180111:ERROR:gl_ozone_egl.cc(20)] GLSurfaceEGL::InitializeOneOff failed.
machine # [1084:1084:1101/104305.189760:ERROR:viz_main_impl.cc(161)] Exiting GPU process due to errors during initialization
machine # [1092:1092:1101/104305.233470:ERROR:gpu_init.cc(457)] Passthrough is not supported, GL is disabled, ANGLE is
This workaround restores the previous result:
machine # [1004:1004:1101/104551.131190:ERROR:gpu_init.cc(457)] Passthrough is not supported, GL is swiftshader, ANGLE is
The workaround is only required for Chromium, not Google Chrome.