fyne-io/fyne · critical

eglGetDisplay failed\n

Error message

eglGetDisplay failed\n

What it means

After opening the X display, x11.c calls eglGetDisplay(x_dpy) to obtain the EGL display for it. Returning EGL_NO_DISPLAY means the installed EGL could not adopt this X display: missing X11 EGL platform libraries, or an EGL stack that only supports other platforms (surfaceless, wayland, device). The process prints 'eglGetDisplay failed' and exits(1).

Solutions

1. Install the Mesa X11 EGL platform pieces: apt install libegl1 libegl-mesa0 libglvnd0 libgl1-mesa-dri
2. Force platform selection: EGL_PLATFORM=x11 ./yourapp
3. Update Mesa/glvnd to repair ICD discovery (check /usr/share/glvnd/egl_vendor.d)
4. On Xwayland sessions, prefer running the Wayland-native path or full Mesa software rendering

Example fix

# before: EGL cannot adopt the X display
./yourapp  # eglGetDisplay failed

# after: install X11 EGL platform modules and pin the platform
sudo apt install libegl1 libegl-mesa0 libglvnd0
EGL_PLATFORM=x11 ./yourapp

func eglDisplayPreflight() error {
	if err := displayPreflight(); err != nil {
		return err
	}
	if _, err := os.Stat("/usr/lib/x86_64-linux-gnu/libEGL_mesa.so.0"); err != nil {
		return fmt.Errorf("Mesa X11 EGL platform missing; install libegl-mesa0 libglvnd0")
	}
	return nil
}

When it happens

Trigger: eglGetDisplay on a valid X display failing because the X11 platform glue (libEGL_x11 / Mesa platform modules) is absent, EGL vendor libraries are misconfigured (glvnd ICDs), or EGL only supports Wayland/surfaceless on this install.

Common situations: Containers with libEGL but without libegl-mesa0/platform modules; Wayland-only stacks where X apps go through Xwayland but EGL vendor libs lack the x11 platform; broken glvnd configurations after partial driver installs.

Related errors

• eglGetConfigAttrib failed\n
• eglChooseConfig failed\n
• eglCreateContext failed\n
• eglCreateWindowSurface failed\n
• eglInitialize failed\n

AI-assisted analysis of fyne-io/fyne@8860ee95c3 (2026-08-15). Data as JSON: /api/errors/a13af9401cb5d975. Report an issue: GitHub.

Appendix: source

Thrown at internal/driver/mobile/app/x11.c:106

	return win;
}

Display *x_dpy;
EGLDisplay e_dpy;
EGLContext e_ctx;
EGLSurface e_surf;
Window win;

void
createWindow(void) {
	x_dpy = XOpenDisplay(NULL);
	if (!x_dpy) {
		fprintf(stderr, "XOpenDisplay failed\n");
		exit(1);
	}
	e_dpy = eglGetDisplay(x_dpy);
	if (!e_dpy) {
		fprintf(stderr, "eglGetDisplay failed\n");
		exit(1);
	}
	EGLint e_major, e_minor;
	if (!eglInitialize(e_dpy, &e_major, &e_minor)) {
		fprintf(stderr, "eglInitialize failed\n");
		exit(1);
	}
	eglBindAPI(EGL_OPENGL_ES_API);
	win = new_window(x_dpy, e_dpy, 500, 1000, &e_ctx, &e_surf);

	wm_delete_window = XInternAtom(x_dpy, "WM_DELETE_WINDOW", True);
	if (wm_delete_window != None) {
		XSetWMProtocols(x_dpy, win, &wm_delete_window, 1);
	}

	XMapWindow(x_dpy, win);
	if (!eglMakeCurrent(e_dpy, e_surf, e_surf, e_ctx)) {
		fprintf(stderr, "eglMakeCurrent failed\n");

View on GitHub (pinned to 8860ee95c3)