gst-plugins-base-libs-scan: symbol lookup error

[Dengke Du]

Hi all, when I build gst-plugins-base, I meet the following error:

My env:

OS: Ubuntu 16.04.5 LTS

gstreamer-plugins-base: 1.14.2

build command:

meson gst-plugins-base-1.14.2 gst-plugins-base-1.14.2-build

cd gst-plugins-base-1.14.2-build

ninja [success]

ninja install [failed]

Error:

Error in gtkdoc helper script:
'gtkdoc-scangobj' failed with status 127
./gst-plugins-base-libs-scan: symbol lookup error: 
../gst-plugins-base-1.14.2-build/gst-libs/gst/audio/libgstaudio-1.0.so.0: 
undefined symbol: gst_aggregator_get_type
Scan failed:

Why? I need your help.