RUSTSEC-2020-0077: memmap is unmaintained about reducer HOT 3 CLOSED

memmap v0.7.0
└── smithay-client-toolkit v0.6.6
    └── smithay-clipboard v0.4.0
        └── copypasta v0.6.3
            └── conrod_core v0.74.0
                └── conrod_glium v0.74.0
                    [dev-dependencies]
                    └── reducer v3.0.0 (/home/bruno/Projects/rust/reducer)
                [dev-dependencies]
                └── reducer v3.0.0 (/home/bruno/Projects/rust/reducer)

cargo tree --invert memmap
error: package ID specification `memmap` did not match any packages