docker编译的时候
FROM ubuntu:latest
RUN apt-get update && apt-get install -y g++ llvm lcov 报错： repository-is-not-signed-in-docker-build
Err:2 http://archive.ubuntu.com/ubuntu bionic InRelease
At least one invalid signature was encountered.
Err:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
At least one invalid signature was encountered.
Err:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
At least one invalid signature was encountered.
Err:4 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
At least one invalid signature was encountered.
Reading package lists...
W: GPG error: http://archive.ubuntu.com/ubuntu bionic InRelease: At least one invalid signature was encountered.
E: The repository 'http://archive.ubuntu.com/ubuntu bionic InRelease' is not signed.
W: GPG error: http://security.ubuntu.com/ubuntu bionic-security InRelease: At least one invalid signature was encountered.
E: The repository 'http://security.ubuntu.com/ubuntu bionic-security InRelease' is not signed.
W: GPG error: http://archive.ubuntu.com/ubuntu bionic-updates InRelease: At least one invalid signature was encountered.
E: The repository 'http://archive.ubuntu.com/ubuntu bionic-updates InRelease' is not signed.
W: GPG error: http://archive.ubuntu.com/ubuntu bionic-backports InRelease: At least one invalid signature was encountered.
E: The repository 'http://archive.ubuntu.com/ubuntu bionic-backports InRelease' is not signed.解决办法：
docker system df
docker image prune
docker container prune