after some digging in, it turned out it's permission issue.
anyway, I came across, a same post in ask Ubuntu,
website. It uses TrashCli to do this in terminal.
here is the steps: (you can check the original post HERE)
- Install trash-cli:
$sudo apt-get install trash-cli
- Put files in the trash with:
$trash file1 file2
- List files in trash:
$trash-list
- Empty trash with:
$trash-empty
