dcpaccess.py - "concat: Invalid stream specifier: v"

[matmat]

I think maybe something with the ffmpeg options is not right. I get this when trying out dcpaccess.py:

$ ./dcpaccess.py /dcp/GFF2020-INGEST/ALI-NINA/
There were no audio delays.
There were no video delays.
['ffmpeg', '-lowres', '0', '-f', 'concat', '-safe', '0', '-c:v ', 'libopenjpeg', '-i', '/tmp/_video_concat_2020_03_10T17_25_11.txt', '-f', 'concat', '-safe', '0', '-i', '/tmp/_audio_concat_2020_03_10T17_25_11.txt', '-vf', 'lut3d=./26_XYZ-22_Rec709.cube', '-c:v', 'libx264', '-pix_fmt', 'yuv420p', '-crf', '19', '-preset', 'veryfast', '-c:a', 'aac', '/home/mhm/Desktop/_muxed_2020_03_10T17_25_11.mkv']
ffmpeg version 4.2.2-1+b1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9 (Debian 9.2.1-28)
  configuration: --prefix=/usr --extra-version=1+b1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[mxf @ 0x559e676ff000] "OPAtom" with 2 ECs - assuming OP1a
[jpeg2000 @ 0x559e67707400] End mismatch 1
    Last message repeated 4 times
[concat @ 0x559e676f5600] Invalid stream specifier: v .
    Last message repeated 1 times