apt によるパッケージ管理

$ apt-cache showpkg xrdp
Package: xrdp
Versions:
0.9.17-2~bpo11+rpt1 (/var/lib/apt/lists/archive.raspberrypi.org_debian_dists_bullseye_main_binary-arm64_Packages) (/var/lib/dpkg/status)
 Description Language:
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_binary-arm64_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_binary-armhf_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language: en
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_i18n_Translation-en
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/archive.raspberrypi.org_debian_dists_bullseye_main_binary-arm64_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/archive.raspberrypi.org_debian_dists_bullseye_main_binary-armhf_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9

0.9.12-1.1 (/var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_binary-arm64_Packages)
 Description Language:
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_binary-arm64_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_binary-armhf_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language: en
                 File: /var/lib/apt/lists/deb.debian.org_debian_dists_bullseye_main_i18n_Translation-en
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/archive.raspberrypi.org_debian_dists_bullseye_main_binary-arm64_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9
 Description Language:
                 File: /var/lib/apt/lists/archive.raspberrypi.org_debian_dists_bullseye_main_binary-armhf_Packages
                  MD5: 330bdf2ad3e2031a5164fd15aa25e2e9


Reverse Depends:
  xrdp-dbgsym,xrdp 0.9.17-2~bpo11+rpt1
  xrdp:armhf,xrdp
  education-ltsp-server,xrdp
  xrdp:armhf,xrdp
Dependencies:
0.9.17-2~bpo11+rpt1 - init-system-helpers (2 1.54~) adduser (0 (null)) lsb-base (2 3.0-6) ssl-cert (0 (null)) libc6 (2 2.17) libfuse2 (2 2.6) libjpeg62-turbo (2 1.3.1) libopus0 (2 1.1) libpam0g (2 0.99.7.1) libssl1.1 (2 1.1.0) libx11-6 (0 (null)) libxfixes3 (0 (null)) libxrandr2 (0 (null)) fuse (0 (null)) xorgxrdp (0 (null)) guacamole (0 (null)) xrdp:armhf (32 (null))
0.9.12-1.1 - init-system-helpers (2 1.54~) adduser (0 (null)) lsb-base (2 3.0-6) ssl-cert (0 (null)) libc6 (2 2.17) libfuse2 (2 2.6) libjpeg62-turbo (2 1.3.1) libopus0 (2 1.1) libpam0g (2 0.99.7.1) libssl1.1 (2 1.1.0) libx11-6 (0 (null)) libxfixes3 (0 (null)) libxrandr2 (0 (null)) fuse (0 (null)) xorgxrdp (0 (null)) guacamole (0 (null)) xrdp-pulseaudio-installer (0 (null)) xrdp:armhf (32 (null))
Provides:
0.9.17-2~bpo11+rpt1 -
0.9.12-1.1 -
Reverse Provides:

$ sudo apt install xrdp=0.9.12-1.1