No, `dirname` is correct. The goal of `ln -s dirname/ linkname` is that even if you accidentally do `cp file linkname` (note without slash) when dirname is gone

No, `dirname` is correct. The goal of `ln -s dirname/ linkname` is that even if you accidentally do `cp file linkname` (note without slash) when dirname is gone, it will error out. Without the trailing slash in the ln command, a file (instead of directory) named dirname will be created.