在安装Snap的时候，提示一下错误：

error: system does not fully support snapd: cannot mount squashfs image using "squashfs": mount:
/tmp/sanity-mountpoint-512632615: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error.

[root@nginx ~]# snap install core
error: system does not fully support snapd: cannot mount squashfs image using "squashfs":
       ----- mount: wrong fs type, bad option, bad superblock on /dev/loop0,

       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.

       -----
[root@nginx ~]#

如果你在安装snap来申请证书的时候遇到如上错误时，别紧张，不是什么大问题，是因为squashfs这个东西惹的祸，它是一个只读的文件系统，具体干嘛的这里不再深究，解决办法如下：

[root@nginx ~]# semodule -i /usr/share/selinux/packages/snappy.pp.bz2

执行完就可以了，完活！