Vanilla git-blame

gitblame.vim

" Vanilla git-blame
"
" git-blame current line:
"   :GB
"
" git-blame selected lines:
"   :'<,'>GB
"
" git-blame entire buffer:
"   :%GB

function s:git_blame(line1, line2) abort
    let cmd = printf('git -C %s blame -L %d,%d %s', expand('%:p:h')->shellescape(), a:line1, a:line2, expand('%:t'))
    let git = systemlist(cmd)
    call map(git, {_, i -> printf('git -C %s log -1 --date=relative --pretty=format:"%%an, %%cd • %%s" %s',
            \   expand('%:p:h'),
            \   matchstr(i, '^\^\=\zs[a-z0-9]\+')
            \   )->systemlist()[0]
            \ })
    echo join(git, "\n")
endfunction

command -range GB call s:git_blame(<line1>, <line2>)