can't get source package

[Mikhail Gavrilov]

$ apt-get --version
apt 1.5~beta1 (amd64)
Supported modules:
*Ver: Standard .deb
*Pkg: Debian dpkg interface (Priority 30)
 Pkg: Debian APT solver interface (Priority -1000)
 Pkg: Debian APT planner interface (Priority -1000)
 S.L: 'deb' Debian binary tree
 S.L: 'deb-src' Debian source tree
 Idx: Debian Source Index
 Idx: Debian Package Index
 Idx: Debian Translation Index
 Idx: Debian dpkg status file
 Idx: Debian deb file
 Idx: Debian dsc file
 Idx: Debian control file
 Idx: EDSP scenario file
 Idx: EIPP scenario file

Ubuntu 17.10

$ apt-get source mutterReading package lists... Done
E: You must put some 'source' URIs in your sources.list

But all deb-src are enabled.

$ cat /etc/apt/sources.list
#deb cdrom:[Ubuntu 17.10 _Artful Aardvark_ - Alpha amd64 (20170714)]/ artful main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ru.archive.ubuntu.com/ubuntu/ artful main restricted
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://ru.archive.ubuntu.com/ubuntu/ artful-updates main restricted
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://ru.archive.ubuntu.com/ubuntu/ artful universe
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful universe
deb http://ru.archive.ubuntu.com/ubuntu/ artful-updates universe
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://ru.archive.ubuntu.com/ubuntu/ artful multiverse
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful multiverse
deb http://ru.archive.ubuntu.com/ubuntu/ artful-updates multiverse
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://ru.archive.ubuntu.com/ubuntu/ artful-backports main restricted universe multiverse
deb-src http://ru.archive.ubuntu.com/ubuntu/ artful-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu artful partner
# deb-src http://archive.canonical.com/ubuntu artful partner

deb http://security.ubuntu.com/ubuntu artful-security main restricted
deb-src http://security.ubuntu.com/ubuntu artful-security main restricted
deb http://security.ubuntu.com/ubuntu artful-security universe
deb-src http://security.ubuntu.com/ubuntu artful-security universe
deb http://security.ubuntu.com/ubuntu artful-security multiverse
deb-src http://security.ubuntu.com/ubuntu artful-security multiverse

[Julian Andres Klode (juliank)]

Did you run apt update?

[Hans Joachim Desserud (hjd)]

Could you please run `sudo apt update` and see if that resolves the issue?

Update needs to be run after changing repositories, otherwise apt won't know about the contents of the new ones.

[Launchpad Janitor (janitor)]

[Expired for apt (Ubuntu) because there has been no activity for 60 days.]