Arch Linux install with makepkg -si chmod: changing permissions of '/mnt/storage/downloads/office/onlyoffice/onlyoffice-bin/src': Operation not permitted

I do the same as here stand:

full error:
==> Making package: onlyoffice-bin 8.1.0-1 (Tue 09 Jul 2024 04:05:33 PM CEST)
==> Checking runtime dependencies…
==> Checking buildtime dependencies…
chmod: changing permissions of ‘/mnt/storage/downloads/office/onlyoffice/onlyoffice-bin/src’: Operation not permitted

==> ERROR: An unknown error has occurred. Exiting…
User defined signal 1

Hello @testware73

Can you specify which AUR returns this error exactly? I see your another post about Yay, which leaves Trizen or Pikaur.