~> tree -d /proc/self/
    /proc/self/
    |-- attr
    |-- cwd -> /proc
    |-- fd
    |   `-- 3 -> /proc/15589/fd
    |-- fdinfo
    |-- net
    |   |-- dev_snmp6
    |   |-- netfilter
    |   |-- rpc
    |   |   |-- auth.rpcsec.context
    |   |   |-- auth.rpcsec.init
    |   |   |-- auth.unix.gid
    |   |   |-- auth.unix.ip
    |   |   |-- nfs4.idtoname
    |   |   |-- nfs4.nametoid
    |   |   |-- nfsd.export
    |   |   `-- nfsd.fh
    |   `-- stat
    |-- root -> /
    `-- task
        `-- 15589
            |-- attr
            |-- cwd -> /proc
            |-- fd
            | `-- 3 -> /proc/15589/task/15589/fd
            |-- fdinfo
            `-- root -> /

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