Use dev-libs/libuv backend.

Packages describing “libuv” as local USE flag

Package “libuv” Flag Description
net-misc/aria2 Use dev-libs/libuv backend.
net-libs/libwebsockets Support asynchronous I/O via dev-libs/libuv
dev-scheme/bigloo Enable libuv support
net-dns/getdns Enable dev-libs/libuv support
sci-libs/gloo Enable libuv support

All packages providing a “libuv” USE flag (5)