Astropy: TST: mpldev 작업이 실패했습니다.

예시 로그: https://circleci.com/gh/astropy/astropy/40859

_________________________ TestFrame.test_custom_frame __________________________
Error: Image files did not match.
  RMS Value: 3.054658327865819
  Expected:  
    /root/project/results/tmpx8od4j4o/baseline-test_custom_frame.png
  Actual:    
    /root/project/results/tmpx8od4j4o/test_custom_frame.png
  Difference:
    /root/project/results/tmpx8od4j4o/test_custom_frame-failed-diff.png
  Tolerance: 
    0
____________________ TestBasic.test_overlay_features_image _____________________
Error: Image files did not match.
  RMS Value: 1.437936407186045
  Expected:  
    /root/project/results/tmpzw3mi0_s/baseline-test_overlay_features_image.png
  Actual:    
    /root/project/results/tmpzw3mi0_s/test_overlay_features_image.png
  Difference:
    /root/project/results/tmpzw3mi0_s/test_overlay_features_image-failed-diff.png
  Tolerance: 
    0
_______________________ TestBasic.test_cube_slice_image ________________________
Error: Image files did not match.
  RMS Value: 2.2366771357026476
  Expected:  
    /root/project/results/tmpq19zge8g/baseline-test_cube_slice_image.png
  Actual:    
    /root/project/results/tmpq19zge8g/test_cube_slice_image.png
  Difference:
    /root/project/results/tmpq19zge8g/test_cube_slice_image-failed-diff.png
  Tolerance: 
    0
______________________ TestBasic.test_changed_axis_units _______________________
Error: Image files did not match.
  RMS Value: 2.2538393169582136
  Expected:  
    /root/project/results/tmp5wjvfo93/baseline-test_changed_axis_units.png
  Actual:    
    /root/project/results/tmp5wjvfo93/test_changed_axis_units.png
  Difference:
    /root/project/results/tmp5wjvfo93/test_changed_axis_units-failed-diff.png
  Tolerance: 
    0
_________________________ TestBasic.test_ticks_labels __________________________
Error: Image files did not match.
  RMS Value: 5.4934233406865705
  Expected:  
    /root/project/results/tmp8fwqvg1e/baseline-test_ticks_labels.png
  Actual:    
    /root/project/results/tmp8fwqvg1e/test_ticks_labels.png
  Difference:
    /root/project/results/tmp8fwqvg1e/test_ticks_labels-failed-diff.png
  Tolerance: 
    0
__________________________ TestBasic.test_hms_labels ___________________________
Error: Image files did not match.
  RMS Value: 3.814848183960492
  Expected:  
    /root/project/results/tmphw2hhhw8/baseline-test_hms_labels.png
  Actual:    
    /root/project/results/tmphw2hhhw8/test_hms_labels.png
  Difference:
    /root/project/results/tmphw2hhhw8/test_hms_labels-failed-diff.png
  Tolerance: 
    0
=============== 6 failed, 432 passed, 3 skipped in 22.47 seconds ===============