apt install tvheadend
The following packages have unmet dependencies:tvheadend : Depends: libssl1.0.0 (>= 1.0.0) but it is not installableE: Unable to correct problems, you have held broken packages.
my sources are defaults:
deb http://httpredir.debian.org/debian stretch main contrib non-free
#deb-src http://httpredir.debian.org/debian stretch main contrib non-free
deb http://httpredir.debian.org/debian stretch-updates main contrib non-free
#deb-src http://httpredir.debian.org/debian stretch-updates main contrib non-fr$
deb http://httpredir.debian.org/debian stretch-backports main contrib non-free
#deb-src http://httpredir.debian.org/debian stretch-backports main contrib non-$
deb http://security.debian.org/ stretch/updates main contrib non-free
#deb-src http://security.debian.org/ stretch/updates main contrib non-free
workaround: aptitude install tvheadend
it solves problem, but something still is wrong.