Debian
Debian Sid：將單個軟體包降級到“以前的版本”
我很高興地執行著一個最先進的 Debian Sid 工作站。
不幸的是，我發生了“上游回歸”（network-manager-vpnc 破壞了 1.2.7 -> 1.2.8）
因此，我需要“降級”到以前的版本。
我知道我應該能夠做到這一點：
sudo apt install network-manager-vpnc=1.2.7但這似乎對 Sid 不起作用：
sudo apt policy network-manager-vpnc network-manager-vpnc: Installed: 1.2.8-3 Candidate: 1.2.8-3 Version table: *** 1.2.8-3 500 500 http://deb.debian.org/debian sid/main amd64 Packages 100 /var/lib/dpkg/status這意味著只有一個版本可用，因此錯誤不足為奇：
sudo apt install network-manager-vpnc=1.2.7 Reading package lists... Done Building dependency tree... Done Reading state information... Done Package network-manager-vpnc is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Version '1.2.7' for 'network-manager-vpnc' was not found我能做些什麼？
**更新：**正如@Stephen-Kitt 正確指出的那樣，“以前的版本”（1.2.7）從未上傳到 Debian 檔案庫，所以“解決方案”是降級到 1.2.6-3。
進入工作系統的程序（對我來說）是：
mcon@cinderella:/tmp/t$ wget http://ftp.it.debian.org/debian/pool/main/n/network-manager-vpnc/network-manager-vpnc_1.2.6-3_amd64.deb --2022-04-28 19:34:27-- http://ftp.it.debian.org/debian/pool/main/n/network-manager-vpnc/network-manager-vpnc_1.2.6-3_amd64.deb Resolving ftp.it.debian.org (ftp.it.debian.org)... 85.94.199.210, 2001:4b78:2000:1::1 Connecting to ftp.it.debian.org (ftp.it.debian.org)|85.94.199.210|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 125812 (123K) [application/vnd.debian.binary-package] Saving to: ‘network-manager-vpnc_1.2.6-3_amd64.deb’ network-manager-vpnc_1.2.6-3_am 100%[====================================================>] 122.86K --.-KB/s in 0.05s 2022-04-28 19:34:27 (2.29 MB/s) - ‘network-manager-vpnc_1.2.6-3_amd64.deb’ saved [125812/125812] mcon@cinderella:/tmp/t$ wget http://ftp.it.debian.org/debian/pool/main/n/network-manager-vpnc/network-manager-vpnc-gnome_1.2.6-3_amd64.deb --2022-04-28 19:34:56-- http://ftp.it.debian.org/debian/pool/main/n/network-manager-vpnc/network-manager-vpnc-gnome_1.2.6-3_amd64.deb Resolving ftp.it.debian.org (ftp.it.debian.org)... 85.94.199.210, 2001:4b78:2000:1::1 Connecting to ftp.it.debian.org (ftp.it.debian.org)|85.94.199.210|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 35592 (35K) [application/vnd.debian.binary-package] Saving to: ‘network-manager-vpnc-gnome_1.2.6-3_amd64.deb’ network-manager-vpnc-gnome_1.2. 100%[====================================================>] 34.76K --.-KB/s in 0.02s 2022-04-28 19:34:56 (1.69 MB/s) - ‘network-manager-vpnc-gnome_1.2.6-3_amd64.deb’ saved [35592/35592] mcon@cinderella:~$ sudo apt remove --purge network-manager-vpnc network-manager-vpnc-gnome Reading package lists... Done Building dependency tree... Done Reading state information... Done The following package was automatically installed and is no longer required: vpnc Use 'sudo apt autoremove' to remove it. The following packages will be REMOVED: network-manager-vpnc* network-manager-vpnc-gnome* 0 upgraded, 0 newly installed, 2 to remove and 0 not upgraded. After this operation, 1,026 kB disk space will be freed. Do you want to continue? [Y/n] (Reading database ... 244048 files and directories currently installed.) Removing network-manager-vpnc-gnome (1.2.8-3) ... Removing network-manager-vpnc (1.2.8-3) ... Processing triggers for dbus (1.14.0-1) ... mcon@cinderella:~$ sudo dpkg -i /tmp/t/network-manager-vpnc_1.2.6-3_amd64.deb Selecting previously unselected package network-manager-vpnc. (Reading database ... 243969 files and directories currently installed.) Preparing to unpack .../network-manager-vpnc_1.2.6-3_amd64.deb ... Unpacking network-manager-vpnc (1.2.6-3) ... Setting up network-manager-vpnc (1.2.6-3) ... Processing triggers for dbus (1.14.0-1) ... mcon@cinderella:~$ sudo dpkg -i /tmp/t/network-manager-vpnc-gnome_1.2.6-3_amd64.deb Selecting previously unselected package network-manager-vpnc-gnome. (Reading database ... 244039 files and directories currently installed.) Preparing to unpack .../network-manager-vpnc-gnome_1.2.6-3_amd64.deb ... Unpacking network-manager-vpnc-gnome (1.2.6-3) ... Setting up network-manager-vpnc-gnome (1.2.6-3) ... mcon@cinderella:~$然後，在檢查它確實有效之後：
mcon@cinderella:/tmp/t$ sudo apt-mark hold network-manager-vpnc network-manager-vpnc set on hold. mcon@cinderella:/tmp/t$ sudo apt-mark hold network-manager-vpnc-gnome network-manager-vpnc-gnome set on hold.非常感謝@Stephen
如果您使用的是 Debian，我懷疑舊版本是 1.2.7，因為它從未上傳到檔案中。請注意，對於
apt’s=語法，您需要指定完整的包版本，例如“1.2.8-3”。無論如何，您可以在 snapshot.debian.org 上找到過去 15 年上傳到檔案的軟體包的所有版本；這包括
network-manager-vpnc. 在那裡下載適當的軟體包，安裝它（使用dpkg -i），然後暫停它（apt-mark hold network-manager-vpnc），這樣它就不會再次升級。您可以
apt為特定快照配置源；有關詳細資訊，請參閱Debian 10：升級到特定的次要版本 (10.10)。您可能還會發現為什麼以前版本的 Debian 軟體包會在軟體包儲存庫中消失？（與版本控制的系統配置高度相關）相關。還請送出一個錯誤（
reportbug network-manager-vpnc），以便其他人可以了解回歸併希望它可以修復。