Use x11-libs/libdrm for more verbose diagnostics.

Packages describing “drm” as local USE flag

Package “drm” Flag Description
app-misc/ddcutil Use x11-libs/libdrm for more verbose diagnostics.
dev-libs/efl Enable DRM engine
net-misc/tigervnc Build with DRM support
dev-libs/weston Enable drm compositor support
media-plugins/gst-plugins-vaapi Enable DRM renderer
x11-misc/picom Enable support for using drm for vsync
media-video/mpv Enable Kernel Mode Setting / Direct Rendering Manager based video output
media-video/libva-utils Enables VA/DRM API support.
x11-libs/libva Enables VA/DRM API support.
x11-libs/libva-compat Enables VA/DRM API support.
sys-apps/kmscon Enable Linux DRM for backend
x11-misc/compton Enable VSync with DRM_IOCTL_WAIT_VBLANK

All packages providing a “drm” USE flag (3)