How to output a permanently delete comment link?

I’m trying to output a “delete comment” link on the front-end. Here’s my attempt so far:

printf(
    '<a href="https://wordpress.stackexchange.com/questions/269898/%s">%s</a>',
    wp_nonce_url(
        admin_url( "comment.php?c=$comment_id&action=deletecomment" ),
        'delete-comment_' . $comment_id
    ),
    __( 'Delete comment', 'text-domain' )
);

I’ve added edit_comment cap to the author role. However, when I log in as an author and click on Delete comment, I get the following message on a white screen of death:

Sorry, you are not allowed to edit comments on this post.

Thank you for creating with WordPress.

Version 4.7.4

How can I output a permanently delete comment link which works?

After briefly testing, the code snippet from OP seems to work:

printf(
    '<a href="https://wordpress.stackexchange.com/questions/269898/%s">%s</a>',
    wp_nonce_url(
        admin_url( "comment.php?c=$comment_id&action=deletecomment" ),
        'delete-comment_' . $comment_id
    ),
    esc_html__( 'Delete comment', 'text-domain' )
);

But it looks like we have to make sure that the author is only deleting comments on hir own post, otherwise it will look for the edit_others_posts and edit_published_posts primitive capabilities.

The edit_comment is not a primitive capability, so instead we have to look at the map_meta_cap() function to see what primitive capabilities it relies on. There we can see that edit_comment is a meta capability that uses:

$caps = map_meta_cap( 'edit_post', $user_id, $post->ID );

for non-orphaned comments. Then we have to look at the part where the edit_post meta capability maps to other primitive capabilities. There are few possible mappings there, e.g. to edit_others_posts and edit_published_posts primitive capabilities.

Jean Galea has written a great article on roles and capabilities, where it says:

• Primitive capabilities are assigned to user roles.
• Meta capabilities never should be assigned to a role.