[MacOS] improve errexit option handling (#8432)

* [MacOS] improve errexit option handling

* Prevent prompting for override when unzipping

* Explicitly allow failing when installing virtualbox

* Remove libtcl symlinks

* Add debug output

images/macos/provision/utils/utils.sh

@@ -15,15 +15,24 @@ download_with_retries() {
         local COMMAND="curl $URL -4 -sL -o '$DEST/$NAME' -w '%{http_code}'"
     fi
 
+    # Save current errexit state and disable it to prevent unexpected exit on error
+    if echo $SHELLOPTS | grep '\(^\|:\)errexit\(:\|$\)' > /dev/null;
+    then
+        local ERR_EXIT_ENABLED=true
+    else
+        local ERR_EXIT_ENABLED=false
+    fi
+    set +e
+
     echo "Downloading '$URL' to '${DEST}/${NAME}'..."
     retries=20
     interval=30
     while [ $retries -gt 0 ]; do
         ((retries--))
-        # Temporary disable exit on error to retry on non-zero exit code
-        set +e
+        test "$ERR_EXIT_ENABLED" = true && set +e
         http_code=$(eval $COMMAND)
         exit_code=$?
+        test "$ERR_EXIT_ENABLED" = true && set -e
         if [ $http_code -eq 200 ] && [ $exit_code -eq 0 ]; then
             echo "Download completed"
             return 0
@@ -31,8 +40,6 @@ download_with_retries() {
             echo "Error — Either HTTP response code for '$URL' is wrong - '$http_code' or exit code is not 0 - '$exit_code'. Waiting $interval seconds before the next attempt, $retries attempts left"
             sleep 30
         fi
-        # Enable exit on error back
-        set -e
     done
 
     echo "Could not download $URL"