Running npm install with libuv 1.7.0 caused freezes. I've tried version 1.7.5 and the problem went away (tried on 2 machines). Please consider removing from portage if nothing else depends on it.
I've tried nodejs 0.12.x and also 4.1.x and 4.2.x, had problems with all versions.
We should bump libuv to 1.8.0 since it's required for nodejs 5.4+.
libuv 1.8.0 is available and depended upon for 5.x and soon 4.x. Does this work for you?
Yes, just tested libuv-1.8.0 with nodejs-5.7.1, works like a charm!
1.8.0 in the tree