Fix rare case when apt and rpm package managers are found (#5827)

automated install/basic-install.sh

@@ -484,9 +484,8 @@ build_dependency_package(){
 
         # Move back into the directory the user started in
         popd &> /dev/null || return 1
-    fi
 
-    if is_command rpm; then
+    elif is_command rpm; then
         # move into the tmp directory
         pushd /tmp &>/dev/null || return 1
 
@@ -517,6 +516,13 @@ build_dependency_package(){
 
         # Move back into the directory the user started in
         popd &> /dev/null || return 1
+
+    # If neither apt-get or yum/dnf package managers were found
+    else
+        # we cannot build required packages
+        printf "  %b No supported package manager found\\n" "${CROSS}"
+        # so exit the installer
+        exit 1
     fi
 
     # Remove the build directory
@@ -1511,10 +1517,8 @@ install_dependent_packages() {
             printf "  %b Error: Unable to find Pi-hole dependency meta package.\\n" "${COL_LIGHT_RED}"
             return 1
         fi
-    fi
-
     # Install Fedora/CentOS packages
-    if is_command rpm; then
+    elif is_command rpm; then
         if [ -f /tmp/pihole-meta.rpm ]; then
             eval "${PKG_INSTALL}" "/tmp/pihole-meta.rpm"
             rm /tmp/pihole-meta.rpm
@@ -1523,7 +1527,14 @@ install_dependent_packages() {
             return 1
         fi
 
+    # If neither apt-get or yum/dnf package managers were found
+    else
+        # we cannot install the dependency package
+        printf "  %b No supported package manager found\\n" "${CROSS}"
+        # so exit the installer
+        exit 1
     fi
+
     printf "\\n"
     return 0
 }