.hluresfile not work in NCL ver6.6.2

[gaomin0006]

Describe the bug
I used NCL to draw weather maps of different levels and accuracy. When the level was very high, the size of the image easily
exceeded 100M of the original setting of wsMaximumSize. Then I checked the official website instructions, and put the.hluresfile
in the home directory, the content was as follows: "*wsMaximumSize: 300000000000", but it did not work, I checked the source
code, found the default directory is "~/", so I put the.hluresfile in the ~ directory, it still does not work. I checked the instructions
again and modified the NCARG_USRRESFILE parameter, but it still didn't work.

Provide the following:

• The contents of my NCL script:
  begin
  ti = addfile("./icon_RELHUM_2M_0125.nc", "r")
  t = ti->2r(0,0,:,:)
  res = True
  res@gsnDraw = False
  res@gsnFrame = False
  res@gsnAddCyclic = True
  res@gsnRightString = ""
  res@gsnLeftString = ""
  res@cnFillOn = False
  res@cnLinesOn = True
  res@cnLineLabelsOn = False
  res@cnConstFLabelBackgroundColor = -1
  res@cnLineLabelBackgroundColor = -1
  res@cnConstFLabelOn = False
  res@cnMonoLineColor = False
  res@cnLineColors = (/(/0.,0.,0.,0./),(/0.,0.,1.,1./)/)
  res@cnFillColors = (/(/0.,0.,0.,0./),(/0.,0.,1.,1./)/)
  res@cnLevelSelectionMode = "ManualLevels"
  res@cnLevelSpacingF = 5
  res@lbLabelBarOn = False
  res@vpXF = 0
  res@vpWidthF = 1
  res@vpYF = 1
  res@vpHeightF = 1
  res@tmXBBorderOn = False
  res@tmYLBorderOn = False
  res@tmYRBorderOn = False
  res@tmXTBorderOn = False
  res@tmYLLabelsOn = False
  res@tmXBLabelsOn = False
  res@tmYROn = False
  res@tmYLOn = False
  res@tmXTOn = False
  res@tmXBOn = False
  res@mpFillOn = False
  res@mpOutlineOn = False
  res@mpProjection = "Mercator"
  do zoom=1,16
  ; when zoom in 1 to 7, the resulting image size is less than 100M, it worked and get the png file.
  ; but when zoom in 8 to 16, the resulting image size is greater than 100M, it failed.
  ; the error print 'cairo driver error: error opening output file'. Then comes the problem of hluresFile not working.
  times = 2^zoom
  wtype = "png"
  wtype@wkWidth = 256 * times
  wtype@wkHeight = 256 * times
  wtype@wkBackgroundOpacityF = 0
  wks = gsn_open_wks(wtype, "icon_T_2M_level_" + zoom)
  plot = gsn_csm_contour_map(wks, t, res)
  draw(plot)
  frame(wks)
  end do
  delete(plot)
  delete(res)
  end

Computing environment

• OS: CentOS Linux release 7.8.2003 (Core)
• NCL Version: 6.6.2
• Installation method:
  tar -zxvf ncl_ncarg-6.6.2-CentOS7.6_64bit_gnu485.tar.gz -C /usr/local/ncl-6.6.2
  vim /etc/profile
  export NCARG_ROOT=/usr/local/ncl-6.6.2
  export NCARG_USRRESFILE=~/.hluresfile
  export DISPLAY=:0.0
  PATH=$PATH:$NCARG_ROOT/bin
  export PATH