The real bug here is that procps is calling 'start' from the maintainer script at all. 'start' is not a standardized maintainer script interface; we should be calling 'invoke-rc.d' instead for all services, including those with upstart jobs. If this were fixed, I believe pbuilder uses an appropriate policy-rc.d in its chroots to avoid accidentally starting services.
The real bug here is that procps is calling 'start' from the maintainer script at all. 'start' is not a standardized maintainer script interface; we should be calling 'invoke-rc.d' instead for all services, including those with upstart jobs. If this were fixed, I believe pbuilder uses an appropriate policy-rc.d in its chroots to avoid accidentally starting services.