[sagher]

Hi experts. i have facing a problem every time i try to upgrade my Debian 9. the log is following.
Preconfiguring packages ...
setting xserver-xorg-legacy/xwrapper/allowed_users from configuration file
(Reading database ... 61756 files and directories currently installed.)
Preparing to unpack .../bsdutils_1%3a2.32.1-0.1_amd64.deb ...
Unpacking bsdutils (1:2.32.1-0.1) over (1:2.32-0.4) ...
Setting up bsdutils (1:2.32.1-0.1) ...
(Reading database ... 61756 files and directories currently installed.)
Preparing to unpack .../libc6_2.27-6_amd64.deb ...
dpkg: error processing archive /var/cache/apt/archives/libc6_2.27-6_amd64.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
Errors were encountered while processing:
 /var/cache/apt/archives/libc6_2.27-6_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)


please help me to fix this. i read many articles but no one fix it.