opencv: error: (-2:Unspecified error) Can't initialize GTK backend in function 'cvInitSystem'

System information (version)

• OpenCV => 3.4
• Operating System / Platform => aarch64 (debian based OS)
• Compiler => g++ 8.3.0

Detailed description

I have opencv as an external dependency that I compile from source like this:

ExternalProject_Add(opencv
  GIT_REPOSITORY https://github.com/opencv/opencv
  GIT_TAG "3.4"
  SOURCE_DIR opencv
  BINARY_DIR opencv-build
  CMAKE_ARGS
    -DCMAKE_BUILD_TYPE=RELEASE 
    -DFORCE_VTK=ON
    -DWITH_TBB=ON
    -DWITH_V4L=ON
    -DWITH_QT=OFF
    -DWITH_GTK_2_x=ON
    -DWITH_OPENGL=ON
    -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/opencv_install
)
set(OPENCV_INCLUDE_DIR ${CMAKE_BINARY_DIR}/opencv_install/include/)
set(OPENCV_LIBRARY_DIR ${CMAKE_BINARY_DIR}/opencv_install/lib/)
set(OPENCV_LIBRARIES opencv_imgproc opencv_core opencv_highgui opencv_video opencv_videoio opencv_imgcodecs opencv_features2d)
if(EXISTS "${CMAKE_BINARY_DIR}/opencv_install/share/OpenCV/OpenCVConfig.cmake")
    include(${CMAKE_BINARY_DIR}/opencv_install/share/OpenCV/OpenCVConfig.cmake)
    add_custom_target(rerun)
else()
    add_custom_target(rerun ${CMAKE_COMMAND} ${CMAKE_SOURCE_DIR} DEPENDS opencv)
endif()

Everything compiles just fine until I run the program, an error like this appears:

terminate called after throwing an instance of 'cv::Exception'
  what():  OpenCV(3.4.12-pre) /media/sd/nam-detect/edgetpu-detection-camera/build/opencv/modules/highgui/src/window_gtk.cpp:624: error: (-2:Unspecified error) Can't initialize GTK backend in function 'cvInitSystem'

Aborted

libgtk2 is definitely installed:

$ sudo apt search libgtk2.0-dev
Sorting... Done
Full Text Search... Done
libgtk2.0-dev/eagle,now 2.24.32-3 arm64 [installed]
  development files for the GTK+ library

Steps to reproduce

This code, which used to works without issue: https://github.com/Namburger/edgetpu-detection-camera We are only seeing this behavior on one of the system o_0

Any suggestion would be highly appreciated!