package sudo 1.8.9p5-1ubuntu1.2 failed to install/upgrade: EOF on stdin at conffile prompt

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ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: sudo 1.8.9p5-1ubuntu1.2
ProcVersionSignature: Ubuntu 3.13.0-32.57~precise1-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
NonfreeKernelModules: bnep rfcomm bluetooth gpio_ich lpc_ich acpi_power_meter i7core_edac ioatdma edac_core ipmi_si mac_hid igb hid_generic ses enclosure dca usbhid i2c_algo_bit bnx2x hid bnx2 megaraid_sas mdio
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
Date: Mon Mar 21 03:34:16 2016
DuplicateSignature: package:sudo:1.8.9p5-1ubuntu1.2:EOF on stdin at conffile prompt
ErrorMessage: EOF on stdin at conffile prompt
InstallationDate: Installed on 2014-08-29 (570 days ago)
InstallationMedia: Ubuntu-Server 12.04.5 LTS "Precise Pangolin" - Release amd64 (20140806.1)
RelatedPackageVersions:
 dpkg 1.17.5ubuntu5.5
 apt 1.0.1ubuntu2.11
SourcePackage: sudo
Title: package sudo 1.8.9p5-1ubuntu1.2 failed to install/upgrade: EOF on stdin at conffile prompt
UpgradeStatus: Upgraded to trusty on 2016-03-21 (0 days ago)
modified.conffile..etc.sudoers: [modified]
mtime.conffile..etc.sudoers: 2014-09-14T22:56:04.381148