SeleniumHQ/selenium · warning

None of the following is a %s version of Xlib:

Error message

None of the following is a %s version of Xlib:

What it means

This is a stderr diagnostic, not a raised exception, emitted by get_xlib_handle() in Selenium's Linux native helper x_ignore_nofocus.so. After scanning the five hardcoded libX11.so.6 candidate paths and the LD_LIBRARY_PATH-derived paths (find_xlib_by_env) and ELF-checking each against the required machine type (EM_386 for 32-bit, EM_X86_64 for 64-bit, chosen via is_32bit_system()/is_emulated_32bit()), none matched. The function prints this line, then lists each candidate, then returns NULL, which disables the focus-stealing-prevention shim and degrades native-event focus handling. It is the root-cause line; the per-path ' %s\n' lines that follow are its continuation.

Source

Thrown at cpp/linux-specific/x_ignore_nofocus.c:630

  int locations_len = sizeof(possible_locations) / sizeof(char*);

  uint16_t required_lib_arch;
  if (is_32bit_system() || is_emulated_32bit()) {
    required_lib_arch = EM_386;
  } else {
    required_lib_arch = EM_X86_64;
  }
  int suitable_xlib_index = find_xlib_by_arch(possible_locations, locations_len, required_lib_arch);
  int found_library = FALSE;
  if (suitable_xlib_index >= 0) {
    snprintf(library, MAX_LIBRARY_PATH, "%s", possible_locations[suitable_xlib_index]);
    found_library = TRUE;
  } else {
    found_library = find_xlib_by_env(library, required_lib_arch);
  }
  if (found_library == FALSE) {
    const char* desired_arch = (required_lib_arch == EM_386 ? "32-bit" : "64-bit");
    fprintf(stderr, "None of the following is a %s version of Xlib:", desired_arch);
    int i;
    for (i = 0; i < locations_len; i++) {
      fprintf(stderr, " %s\n", possible_locations[i]);
    }
    return NULL;
  }

  ret_handle = dlopen(library, RTLD_LAZY);
  if (ret_handle == NULL) {
    fprintf(stderr, "Failed to dlopen %s\n", library);
    fprintf(stderr, "dlerror says: %s\n", dlerror());
  }

  return ret_handle;
}

void print_event_to_log(Display* dpy, XEvent* ev)
{

View on GitHub (pinned to aa36b38e69)

Solutions

1. Install the architecture-matching libX11: on Debian/Ubuntu 64-bit run `apt-get install -y libx11-6`; for 32-bit on a 64-bit host add `:i386` (`dpkg --add-architecture i386 && apt-get install -y libx11-6:i386`).
2. If libX11 is installed in a non-scanned path, export `LD_LIBRARY_PATH` pointing at the directory containing the correct-arch libX11.so.6 before launching the JVM/browser, so find_xlib_by_env succeeds.
3. Align architectures: run a 64-bit browser with a 64-bit JVM (and libX11), or a 32-bit browser with 32-bit libX11; mixing is the most common trigger.
4. Verify with `file $(ldconfig -p | grep libX11.so.6 | awk '{print $NF}' | head -1)` that the ELF machine type matches the required arch; if not, install the matching package.

Example fix

# before (64-bit JVM, container with only 32-bit libX11)
java -jar selenium-server.jar   # get_xlib_handle prints 'None of the following is a 64-bit version of Xlib:'

# after
apt-get update && apt-get install -y libx11-6
java -jar selenium-server.jar   # find_xlib_by_arch matches /usr/lib/x86_64-linux-gnu/libX11.so.6

#!/usr/bin/env bash
# Run before launching the JVM/Selenium Server on Linux.
REQUIRED_ARCH="64-bit"   # set to 32-bit for a 32-bit browser/JVM

candidates=(
  /usr/lib/libX11.so.6
  /usr/lib/x86_64-linux-gnu/libX11.so.6
  /usr/lib/i386-linux-gnu/libX11.so.6
  /usr/lib64/libX11.so.6
  /usr/lib32/libX11.so.6
)

match=0
for lib in "${candidates[@]}"; do
  [ -f "$lib" ] || continue
  arch=$(file -L "$lib" | grep -o 'ELF 32-bit\|ELF 64-bit')
  if [ "${arch#ELF }" = "$REQUIRED_ARCH" ]; then
    echo "OK: $lib ($arch)"; match=1; break
  fi
  echo "SKIP: $lib ($arch)"
done

if [ "$match" -eq 0 ] && [ -n "$LD_LIBRARY_PATH" ]; then
  for d in "${LD_LIBRARY_PATH//:/ }"; do
    lib="$d/libX11.so.6"; [ -f "$lib" ] || continue
    arch=$(file -L "$lib" | grep -o 'ELF 32-bit\|ELF 64-bit')
    [ "${arch#ELF }" = "$REQUIRED_ARCH" ] && { echo "OK(env): $lib"; match=1; break; }
  done
fi

[ "$match" -eq 1 ] || { echo "FAIL: no $REQUIRED_ARCH libX11 found"; exit 1; }

When it happens

Trigger: get_xlib_handle() runs at JVM/native-helper load time on Linux: required_lib_arch resolves to EM_X86_64 (or EM_386) and find_xlib_by_arch returns -1 for every entry in possible_locations, AND find_xlib_by_env also returns FALSE (no usable LD_LIBRARY_PATH entry of the right arch). Concretely: 64-bit JVM/browser on a host whose libX11.so.6 is only the 32-bit Debian/Ubuntu variant, or vice-versa, or a host where none of the five paths exist at all.

Common situations: Minimal Docker/headless containers that omit libX11 or ship only one architecture; mixed 32/64-bit setups running a 32-bit browser on a 64-bit host without the i386 multilib packages; custom distros whose libX11 lives outside the five scanned locations and LD_LIBRARY_PATH is unset; systems where libX11 was removed during image slimming.

Related errors

• %s
• Failed to dlopen %s
• Unable to obtain browser driver. For more informatio
• Unable to obtain Selenium Manager at ${filePath}
• Error executing command for ${smBinary} with ${args}: ${erro

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/a1013cd64f990c60. Report an issue: GitHub.