You said you installed texinfo from source, this would have placed an
"install-info" in your PATH that is not compatible with the dpkg install-info --
this is why your installs are failing
Remove /usr/local/bin/install-info and your system will work.
There should not be a different solution, you have hosed your system by
installing software that is not from the Ubuntu archive, so there is no
guarantee it will behave correctly. We supply versions of TeTeX and texinfo,
etc. in our archive that are known to work and do not break your system like this.
You said you installed texinfo from source, this would have placed an
"install-info" in your PATH that is not compatible with the dpkg install-info --
this is why your installs are failing
Remove /usr/local/ bin/install- info and your system will work.
There should not be a different solution, you have hosed your system by
installing software that is not from the Ubuntu archive, so there is no
guarantee it will behave correctly. We supply versions of TeTeX and texinfo,
etc. in our archive that are known to work and do not break your system like this.