New software can't be installed, because there is a problem with the software currently installed. Do you want to repair now?

hit Repair

Package operation failed 
The installation or removal of a software package failed.
Details => installArchives()failed:Could not exec dpkg!
Error in function

(synaptic:12725): GLib-CRITICAL **: g_child_watch_add_full: assertion 'pid > 0' failed
Could not exec dpkg!
E: Sub-process /usr/bin/dpkg returned an error code (100)
A package failed to install.  Trying to recover:
sh: 1: dpkg: not found
  • Open a terminal and run sudo apt-get install -f, post the error message.
    – Panther
    May 30, 2014 at 21:29
  • Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages will be REMOVED: skype 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 62.5 kB disk space will be freed. Do you want to continue? [Y/n] y Could not exec dpkg! E: Sub-process /usr/bin/dpkg returned an error code (100) tom@thomas:~$ May 31, 2014 at 0:00

1 Answer 1


Test this:

Open a terminal - Press Ctrl+Alt+T

Run it:

sudo -i
mkdir /tmp/dpkg
cd /tmp/dpkg
wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5.2_i386.deb
# or
wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5.2_amd64.deb
ar x dpkg*.deb data.tar.gz
tar xvzf data.tar.gz ./usr/bin/dpkg
cp ./usr/bin/dpkg /usr/bin/
apt-get update
apt-get install --reinstall dpkg
  • I don't understand very much of coding, but I would like to know what is been doing with that code lines. I have the same problem (g_child_watch_add_full) and I want to be a little more informed to take my decision for this problem. Thanks!
    – Sardinha
    Aug 24, 2014 at 13:19
  • 2
    @pedro-sardinha-u94410: You should use the command man. man sudo - man mkdir - man wget - man ar - man tar - man cp - man apt-get.
    – kyodake
    Nov 8, 2014 at 0:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .