Arch Linux

Great. This symbol is part of the private pangoX api and has been removed in the last update. Recompiling mlt should fix this.

This doesn't make a lot of sense. Do me a favor, install the pax-utils package and run `lddtree /usr/lib/mlt/libmltopencv.so`

No, recompiling mlt doesn't fix it. The undefined symbol is in libpangox itself

> objdump -T /usr/lib/libpangox-1.0.so.0 | grep pango_x_get
0000000000000000 D *UND* 0000000000000000 pango_x_get_shaper_map
0000000000006770 g DF .text 0000000000000015 Base pango_x_get_context
00000000000078f0 g DF .text 0000000000000006 Base pango_x_get_unknown_glyph

Installed pax-utils, and got this:

~ > lddtree /usr/lib/mlt/libmltopencv.so
/usr/lib/mlt/libmltopencv.so (interpreter => None)
libmlt.so.6 => /usr/lib/libmlt.so.6
libdl.so.2 => /usr/lib/libdl.so.2
ld-linux-x86-64.so.2 => /usr/lib/ld-linux-x86-64.so.2
libpthread.so.0 => /usr/lib/libpthread.so.0
libopencv_tracking.so.3.2 => /usr/lib/libopencv_tracking.so.3.2
libopencv_video.so.3.2 => /usr/lib/libopencv_video.so.3.2
libopencv_dnn.so.3.2 => /usr/lib/libopencv_dnn.so.3.2
libopencv_highgui.so.3.2 => /usr/lib/libopencv_highgui.so.3.2
libGL.so.1 => /usr/lib/libGL.so.1
libGLX.so.0 => /usr/lib/libGLX.so.0
libX11.so.6 => /usr/lib/libX11.so.6
libxcb.so.1 => /usr/lib/libxcb.so.1
libXau.so.6 => /usr/lib/libXau.so.6
libXdmcp.so.6 => /usr/lib/libXdmcp.so.6
libXext.so.6 => /usr/lib/libXext.so.6
libGLdispatch.so.0 => /usr/lib/libGLdispatch.so.0
libgtk-x11-2.0.so.0 => /usr/lib/libgtk-x11-2.0.so.0
libgmodule-2.0.so.0 => /usr/lib/libgmodule-2.0.so.0
libpangocairo-1.0.so.0 => /usr/lib/libpangocairo-1.0.so.0
libfreetype.so.6 => /usr/lib/libfreetype.so.6
libz.so.1 => /usr/lib/libz.so.1
libbz2.so.1.0 => /usr/lib/libbz2.so.1.0
libpng16.so.16 => /usr/lib/libpng16.so.16
libharfbuzz.so.0 => /usr/lib/libharfbuzz.so.0
libfreetype.so.6 => !!! circular loop !!!
libgraphite2.so.3 => /usr/lib/libgraphite2.so.3
libXfixes.so.3 => /usr/lib/libXfixes.so.3
libatk-1.0.so.0 => /usr/lib/libatk-1.0.so.0
libgio-2.0.so.0 => /usr/lib/libgio-2.0.so.0
libresolv.so.2 => /usr/lib/libresolv.so.2
libmount.so.1 => /usr/lib/libmount.so.1
libblkid.so.1 => /usr/lib/libblkid.so.1
libuuid.so.1 => /usr/lib/libuuid.so.1
librt.so.1 => /usr/lib/librt.so.1
libpangoft2-1.0.so.0 => /usr/lib/libpangoft2-1.0.so.0
libpango-1.0.so.0 => /usr/lib/libpango-1.0.so.0
libthai.so.0 => /usr/lib/libthai.so.0
libdatrie.so.1 => /usr/lib/libdatrie.so.1
libfontconfig.so.1 => /usr/lib/libfontconfig.so.1
libexpat.so.1 => /usr/lib/libexpat.so.1
libgdk-x11-2.0.so.0 => /usr/lib/libgdk-x11-2.0.so.0
libXrender.so.1 => /usr/lib/libXrender.so.1
libXinerama.so.1 => /usr/lib/libXinerama.so.1
libXi.so.6 => /usr/lib/libXi.so.6
libXrandr.so.2 => /usr/lib/libXrandr.so.2
libXcursor.so.1 => /usr/lib/libXcursor.so.1
libXcomposite.so.1 => /usr/lib/libXcomposite.so.1
libXdamage.so.1 => /usr/lib/libXdamage.so.1
libcairo.so.2 => /usr/lib/libcairo.so.2
libpixman-1.so.0 => /usr/lib/libpixman-1.so.0
libEGL.so.1 => /usr/lib/libEGL.so.1
libxcb-shm.so.0 => /usr/lib/libxcb-shm.so.0
libxcb-render.so.0 => /usr/lib/libxcb-render.so.0
libgdk_pixbuf-2.0.so.0 => /usr/lib/libgdk_pixbuf-2.0.so.0
libgobject-2.0.so.0 => /usr/lib/libgobject-2.0.so.0
libffi.so.6 => /usr/lib/libffi.so.6
libglib-2.0.so.0 => /usr/lib/libglib-2.0.so.0
libpcre.so.1 => /usr/lib/libpcre.so.1
libgtkglext-x11-1.0.so.0 => /usr/lib/libgtkglext-x11-1.0.so.0
libGLU.so.1 => /usr/lib/libGLU.so.1
libXmu.so.6 => /usr/lib/libXmu.so.6
libXt.so.6 => /usr/lib/libXt.so.6
libSM.so.6 => /usr/lib/libSM.so.6
libICE.so.6 => /usr/lib/libICE.so.6
libpangox-1.0.so.0 => /usr/lib/libpangox-1.0.so.0
libgdkglext-x11-1.0.so.0 => /usr/lib/libgdkglext-x11-1.0.so.0
libopencv_imgcodecs.so.3.2 => /usr/lib/libopencv_imgcodecs.so.3.2
libjpeg.so.8 => /usr/lib/libjpeg.so.8
libwebp.so.6 => /usr/lib/libwebp.so.6
libtiff.so.5 => /usr/lib/libtiff.so.5
liblzma.so.5 => /usr/lib/liblzma.so.5
libjasper.so.4 => /usr/lib/libjasper.so.4
libIlmImf-2_2.so.22 => /usr/lib/libIlmImf-2_2.so.22
libImath-2_2.so.12 => /usr/lib/libImath-2_2.so.12
libIex-2_2.so.12 => /usr/lib/libIex-2_2.so.12
libIlmThread-2_2.so.12 => /usr/lib/libIlmThread-2_2.so.12
libHalf.so.12 => /usr/lib/libHalf.so.12
libm.so.6 => /usr/lib/libm.so.6
libopencv_imgproc.so.3.2 => /usr/lib/libopencv_imgproc.so.3.2
libtbb.so.2 => /usr/lib/libtbb.so.2
libopencv_core.so.3.2 => /usr/lib/libopencv_core.so.3.2
libstdc++.so.6 => /usr/lib/libstdc++.so.6
libgcc_s.so.1 => /usr/lib/libgcc_s.so.1
libc.so.6 => /usr/lib/libc.so.6

Got to love flyspray's stripping of whitespace. :(

Anyway, it tells me that libgtkglext-x11-1.0.so.0 would be the more likely culprit (libmltopencv.so -> libopencv_tracking.so.3.2 -> libopencv_highgui.so.3.2 -> libgtkglext-x11-1.0.so.0 -> libpangox-1.0.so.0) and that's what would need to be rebuilt under normal circumstances. This isn't normal, though, as arojas already pointed out the problem with libpangox directly.