I receive this error when I install the software.
Basically I want to know which space am I working on.
$sudo apt-get install indicator-workspaces
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package indicator-workspaces is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'indicator-workspaces' has no installation candidate
sudo apt-get update && sudo apt-get upgrade
before?