Quoting
"Removal of SetIndexedPropertiesToExternalArrayData and related APIs which Node has previously relied upon for its Buffer implementation. This has forced a complete rewrite of Buffer, now implemented on top of Uint8Array. Thankfully we had a bit of advance warning from the V8 team although this API change was the primary reason for the io.js v3 delay and the fact that we skipped shipping V8 4.3."
See also
nodejs/node#1451
Quoting
"Removal of SetIndexedPropertiesToExternalArrayData and related APIs which Node has previously relied upon for its Buffer implementation. This has forced a complete rewrite of Buffer, now implemented on top of Uint8Array. Thankfully we had a bit of advance warning from the V8 team although this API change was the primary reason for the io.js v3 delay and the fact that we skipped shipping V8 4.3."
See also
nodejs/node#1451