Defined in /home/build/jenkins/workspace/RockBootstrap19/FLAVOR/master/label/DebianUnstable/dev/autoproj/remotes/orocos.toolchain/orocos.osdeps as

libxslt:
    debian,ubuntu: libxslt1-dev
      gentoo: dev-libs/libxslt
      fedora: libxslt-devel