the tails-installer package in Debian Jessie depends on the 'syslinux'
package, which recommends the 'syslinux-common' package. The later
package won't get installed as a dependency of tails-installer, if
somebody has something like 'Apt::Install-Recommends "false";' in a
config file, which seems to break tails-installer.
I am not sure if this is a bug actually, but would suggest that
tails-installer should properly depend (directly or indirectly) on all
the tools necessary to do its job.