In case you recently tried to update your debian system, and got an error related to libgdbm3 like this:
Preparing to unpack .../libgdbm3_1.8.3-13+b1_i386.deb ...
Unpacking libgdbm3:i386 (1.8.3-13+b1) over (1.8.3-13) ...
dpkg: error processing archive /var/cache/apt/archives/libgdbm3_1.8.3-13+b1_i386.deb (--unpack):
trying to overwrite shared '/usr/share/doc/libgdbm3/changelog.Debian.gz', which is different from other instances of package libgdbm3:i386
Errors were encountered while processing:
/var/cache/apt/archives/libgdbm3_1.8.3-13+b1_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
You can fix this easily by deleting the libdgbm3 changelog file.