You might want to reinstall dpkg by doing the following:
sudo -i
mkdir /tmp/dpkg
cd /tmp/dpkg
Mind that you might want to look whether the download links are still up-too-date
If you are running a 32 bit version of ubuntu
wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5_i386.deb
For 64 bit
wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5.8_amd64.deb
then
ar x dpkg*.deb data.tar.gz
tar xfvz data.tar.gz ./usr/bin/dpkg
Now copy the binary to /usr/bin with
sudo cp ./usr/bin/dpkg /usr/bin
And finally run
sudo apt-get update
sudo apt-get install --reinstall dpkg
原地址：https://askubuntu.com/questions/931115/how-can-i-fix-dpkg-error-code100