buildNpmPackage is built into nixpkgs and pre-fetches dependencies as a fixed-output derivation with network access. npmDepsHash is a placeholder (lib.fakeHash) — the first build will fail with a hash mismatch that reports the correct hash.
buildNpmPackage is built into nixpkgs and pre-fetches dependencies as a fixed-output derivation with network access. npmDepsHash is a placeholder (lib.fakeHash) — the first build will fail with a hash mismatch that reports the correct hash.