Install cmake >= 3.12 on Ubuntu 18 fix, link to repo added

cmake_targets/tools/build_helper

@@ -525,13 +525,14 @@ check_install_soapy () {
     install_soapy_iris_from_source
 }
 
-# for ubuntu 18 we need a special repository to install cmake >= 3.12
+# for ubuntu 18 we need a special repository (https://apt.kitware.com/) to install cmake >= 3.12
 add_cmake_repo () {
-  wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | sudo tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null
-  echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ bionic main' | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
-  $SUDO apt-get update
+  $SUDO $INSTALLER -y install wget
+  wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | $SUDO tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null
+  echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ bionic main' | $SUDO tee /etc/apt/sources.list.d/kitware.list >/dev/null
+  $SUDO $INSTALLER -y update
   $SUDO rm /usr/share/keyrings/kitware-archive-keyring.gpg
-  $SUDO apt-get install kitware-archive-keyring
+  $SUDO $INSTALLER -y install kitware-archive-keyring
 }
 
 check_install_additional_tools (){