Mmmmm
If I understood you well.
It should be like this?
Qt Code:
  1. void MainWindow::on_pb_new_package_clicked()
  2. {
  3. QString install="pwd";//"gksudo apt-get install build-essential devscripts ubuntu-dev-tools debhelper dh-make diff patch gnupg fakeroot lintian pbuilder";
  4. connect(process,SIGNAL(readReadyStandardOutput()),this, SLOT( _readstdoutput()));
  5. process->execute(install);
  6. }
  7.  
  8. void MainWindow::_readstdoutput()
  9. {
  10. ui->textEdit->append(process->readAllStandardOutput());
  11. }
To copy to clipboard, switch view to plain text mode 
But I have my doubts. About this solution, the function _readstdoutput is going to append something that doesn't exist to the textedit?
I tried it, and the program crashes when I make the conection