我尝试下载它，但它不起作用：
$ sudo apt-get install squashfs-tools
Reading package lists... Done
Building dependency tree
Reading state information... Done
squashfs-tools is already the newest version (1:4.3-12+deb10u2).
squashfs-tools set to manually installed.
The following packages were automatically installed and are no longer required:
libva-wayland2 lxplug-volume python-colorzero
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up dphys-swapfile (20100506-5+rpt2) ...
Job for dphys-swapfile.service failed because the control process exited with error code.
See "systemctl status dphys-swapfile.service" and "journalctl -xe" for details.
invoke-rc.d: initscript dphys-swapfile, action "restart" failed.
● dphys-swapfile.service - dphys-swapfile - set up, mount/unmount, and delete a swap file
Loaded: loaded (/lib/systemd/system/dphys-swapfile.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2021-12-15 10:35:51 GMT; 19ms ago
Docs: man:dphys-swapfile(8)
Process: 2027 ExecStart=/sbin/dphys-swapfile setup (code=exited, status=0/SUCCESS)
Process: 2050 ExecStart=/sbin/dphys-swapfile swapon (code=exited, status=255/EXCEPTION)
Main PID: 2050 (code=exited, status=255/EXCEPTION)
Dec 15 10:35:51 pi systemd[1]: Starting dphys-swapfile - set up, mount/unmount, and delete a swap file...
Dec 15 10:35:51 pi dphys-swapfile[2027]: want /var/swap=100MByte, checking existing: keeping it
Dec 15 10:35:51 pi dphys-swapfile[2050]: swapon: /var/swap: swapon failed: Invalid argument
Dec 15 10:35:51 pi systemd[1]: dphys-swapfile.service: Main process exited, code=exited, status=255/EXCEPTION
Dec 15 10:35:51 pi systemd[1]: dphys-swapfile.service: Failed with result 'exit-code'.
Dec 15 10:35:51 pi systemd[1]: Failed to start dphys-swapfile - set up, mount/unmount, and delete a swap file.
dpkg: error processing package dphys-swapfile (--configure):
installed dphys-swapfile package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
dphys-swapfile
E: Sub-process /usr/bin/dpkg returned an error code (1)