Jenkins Debian Glue attempts to use eatmydata which dramatically speed up the build time.
pbuilder has support for it since 0.225. Jenkins Debian Glue then check the target distribution to verify whether it has a recent enough version (and all recent distro beside trusty have one).
The package is added by setting EXTRAPACKAGES=eatmydata which pbuilder build honors to install some more packages. However it is not installed in our build:
sudo DIST=stretch cowbuilder --build xxx.dsc -> Invoking pbuilder forking: pbuilder build ... xxx.dsc I: Installing the build-deps I: user script .../hooks/D01apt.wikimedia.org starting ERROR: ld.so: object 'libeatmydata.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
I blame sudo for not passing the environment variable...