重点有这么一行错误：
Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
Reading package lists... Done
root@DESKTOP-R5MSHA1:~# apt-get updateErr:1 https://mirrors.aliyun.com/debian bullseye InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]Err:2 https://mirrors.aliyun.com/debian-security bullseye-security InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]Err:3 https://mirrors.aliyun.com/debian bullseye-updates InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]Err:4 https://mirrors.aliyun.com/debian bullseye-backports InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]Reading package lists... DoneW: https://mirrors.aliyun.com/debian/dists/bullseye/InRelease: No system certificates available. Try installing ca-certificates.W: https://mirrors.aliyun.com/debian-security/dists/bullseye-security/InRelease: No system certificates available. Try installing ca-certificates.W: https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease: No system certificates available. Try installing ca-certificates.W: https://mirrors.aliyun.com/debian/dists/bullseye-backports/InRelease: No system certificates available. Try installing ca-certificates.W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye/InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]W: Failed to fetch https://mirrors.aliyun.com/debian-security/dists/bullseye-security/InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]W: Failed to fetch 电脑 https://mirrors.aliyun.com/debian/dists/bullseye-backports/InRelease Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]W: Some index files failed to download. They have been ignored, or old ones used instead.
apt-get install --reinstall ca-certificates
然后重新运行 apt-get update：
root@DESKTOP-R5MSHA1:~# apt-get updateHit:1 https://mirrors.aliyun.com/debian bullseye InReleaseGet:2 https://mirrors.aliyun.com/debian-security bullseye-security InRelease [48.4 kB]Hit:3 https://mirrors.aliyun.com/debian bullseye-updates InReleaseGet:4 https://mirrors.aliyun.com/debian bullseye-backports InRelease [49.0 kB]Get:5 https://mirrors.aliyun.com/debian 电脑 bullseye/contrib Sources [43.2 kB]Get:6 https://mirrors.aliyun.com/debian bullseye/non-free Sources [81.2 kB]Get:7 https://mirrors.aliyun.com/debian bullseye/main Sources [8,633 kB]Get:8 https://mirrors.aliyun.com/debian bullseye/non-free amd64 Packages [97.7 kB]Get:9 https://mirrors.aliyun.com/debian bullseye/non-free Translation-en [92.4 kB]Get:10 https://mirrors.aliyun.com/debian bullseye/contrib amd64 Packages [50.6 kB]Get:11 https://mirrors.aliyun.com/debian bullseye/contrib Translation-en [46.9 kB]Get:12 https://mirrors.aliyun.com/debian-security bullseye-security/main Sources [169 kB]Get:13 https://mirrors.aliyun.com/debian-security bullseye-security/main amd64 Packages [200 kB]Get:14 https://mirrors.aliyun.com/debian-security bullseye-security/main Translation-en [129 kB]Get:15 https://mirrors.aliyun.com/debian bullseye-updates/main Sources [4,812 B]Get:16 https://mirrors.aliyun.com/debian bullseye-backports/main Sources [358 kB]Get:17 https://mirrors.aliyun.com/debian bullseye-backports/contrib Sources [2,868 B]Get:18 https://mirrors.aliyun.com/debian bullseye-backports/non-free Sources [4,552 B]Get:19 https://mirrors.aliyun.com/debian bullseye-backports/main amd64 Packages [361 kB]Get:20 https://mirrors.aliyun.com/debian bullseye-backports/main Translation-en [297 kB]Get:21 https://mirrors.aliyun.com/debian bullseye-backports/non-free amd64 Packages [14.3 kB]Get:22 https://mirrors.aliyun.com/debian bullseye-backports/non-free Translation-en [26.6 kB]Get:23 https://mirrors.aliyun.com/debian bullseye-backports/contrib amd64 Packages [4,400 B]Get:24 https://mirrors.aliyun.com/debian bullseye-backports/contrib Translation-en [4,320 B]Fetched 10.7 MB in 2min 3s (86.9 kB/s)Reading package lists... Done
电脑