yelp ftbfs in focal

seen in the second focal test rebuild
https://launchpad.net/ubuntu/+archive/test-rebuild-20200327-focal/+build/18988549/+files/buildlog_ubuntu-focal-amd64.yelp_3.34.0-1_BUILDING.txt.gz

if test -f "data/yelp.appdata.xml"; then d=; else d="./"; fi; \
 if test -n "/usr/bin/appstream-util"; \
  then /usr/bin/appstream-util --nonet validate ${d}data/yelp.appdata.xml; fi \
 && touch data/yelp.appdata.valid
data/yelp.appdata.xml:
(appstream-util:13176): dconf-CRITICAL **: 17:24:25.186: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.186: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.

(appstream-util:13176): dconf-CRITICAL **: 17:24:25.187: unable to create directory '/sbuild-nonexistent/.cache/dconf': Permission denied. dconf will not work properly.
FAILED:
• tag-missing : <content_rating> required [use https://odrs.gnome.org/oars]
• tag-missing : <release> required
Validation of files failed
make[3]: *** [Makefile:4123: data/yelp.appdata.valid] Error 1
make[3]: Leaving directory '/<<PKGBUILDDIR>>'
make[2]: *** [Makefile:3358: check-recursive] Error 1
make[2]: Leaving directory '/<<PKGBUILDDIR>>'
make[1]: *** [Makefile:3654: check] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
dh_auto_test: error: make -j4 check VERBOSE=1 returned exit code 2