我尝试升级pi（配有拉伸）。
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
由于依赖性问题，配置php7时出错。
我试图卸载相关的php7东西。 现在，我尝试过的所有apt-xxx命令都失败了。
例如：
>>:~ $ sudo apt-get purge
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
libapache2-mod-php7.0 php-apcu php-imagick php7.0-cgi php7.0-cli php7.0-common php7.0-curl php7.0-gd php7.0-intl php7.0-json php7.0-mbstring php7.0-mysql php7.0-opcache php7.0-readline php7.0-xml php7.0-zip
0 upgraded, 0 newly installed, 16 to remove and 0 not upgraded.
16 not fully installed or removed.
After this operation, 20.3 MB disk space will be freed.
Do you want to continue? [Y/n]
/usr/bin/dpkg: relocation error: /usr/bin/dpkg: symbol ▒, version GLIBC_2.4 not defined in file libc.so.6 with link time reference
E: Sub-process dpkg --set-selections returned an error code (127)
E: Couldn't record the approved state changes as dpkg selection states
我应该尝试什么？