For 18.04, I have run the tests as follows from the source directory (based on the testing rule in debian/rules and the instructions in doc/fate.texi):
$ debuild -us -uc
$ export LD_LIBRARY_PATH="libavcodec:libavdevice:libavfilter:libavformat:libavresample:libavutil:libpostproc:libswresample:libswscale"
$ cd debian/standard
$ make -j1 fate-rsync SAMPLES=fate-suite/
$ make -j1 fate SAMPLES=fate-suite/
For 18.04, I have run the tests as follows from the source directory (based on the testing rule in debian/rules and the instructions in doc/fate.texi): PATH="libavcode c:libavdevice: libavfilter: libavformat: libavresample: libavutil: libpostproc: libswresample: libswscale"
$ debuild -us -uc
$ export LD_LIBRARY_
$ cd debian/standard
$ make -j1 fate-rsync SAMPLES=fate-suite/
$ make -j1 fate SAMPLES=fate-suite/