Unable to install plugin from .tar.gz

[verdverm]

$ helm install plugin helm-push_0.10.4_linux_amd64.tar.gz
Error: INSTALLATION FAILED: chart illegally contains content outside the base directory: "LICENSE"

helm v3.10.1, though it seems to be the case for some time (helm/helm#5610)

$ tree (of unpacked content)
.
├── LICENSE
├── bin
│   └── helm-cm-push
└── plugin.yaml

[verdverm]

after realizing my typo (reversing install & plugin), I'm seeing a different error

$ helm plugin install ./helm-push_0.10.4_linux_amd64.tar.gz
Error: plugin metadata (plugin.yaml) missing

If I manually unpack the tar into the correct location, it works

mkdir -p $HELM_PLUGIN_DIR/helm-push
tar -xf helm-push_0.10.4_linux_amd64.tar.gz -C $HELM_PLUGIN_DIR/helm-push