Debian 9: Synaptic 패키지 관리자가 명령줄에서 시작되지 않습니다.

Debian 9: Synaptic 패키지 관리자가 명령줄에서 시작되지 않습니다.

이 줄을 입력할 때마다:

sudo pkexec synaptic

시냅틱 패키지 관리자가 열리지만 항상 다음 오류 메시지가 표시됩니다.

E: Could not open file  - open (2: No such file or directory)
E: _cache->open() failed, please report.

오류 상자를 닫으면 시냅스도 닫힙니다. 이 오류를 수정하고 최종적으로 시냅틱을 시작하려면 어떻게 해야 합니까?

@Henrik, 방금 달렸어요

 sudo apt update

터미널에서 생성된 전체 응답은 다음과 같습니다.

Ign:1 http://ftp.us.debian.org/debian stretch InRelease
Get:2 http://deb.debian.org/debian stretch-backports InRelease [91.8 kB]
Hit:3 http://ftp.us.debian.org/debian stretch Release         
Get:5 http://deb.debian.org/debian stretch-backports/main amd64 
Packages.diff/Index [27.8 kB]
Get:6 http://deb.debian.org/debian stretch-backports/main amd64 Packages 
2018-12-24-0808.38.pdiff [622 B]
Get:6 http://deb.debian.org/debian stretch-backports/main amd64 Packages 
2018-12-24-0808.38.pdiff [622 B]
Fetched 120 kB in 1s (75.7 kB/s)
Reading package lists... Done
Building dependency tree       
Reading state information... Done
2 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: http://ftp.us.debian.org/debian/dists/stretch/Release.gpg: The key(s) 
in the keyring /etc/apt/trusted.gpg are ignored as the file is not 
readable by user '_apt' executing apt-key.
W: http://deb.debian.org/debian/dists/stretch-backports/InRelease: The 
key(s) in the keyring /etc/apt/trusted.gpg are ignored as the file is not 
readable by user '_apt' executing apt-key.

관련 정보