node.js - node-gyp rebuild build error 'make' failed npm install -

getting these errors using npm install on osx 10.10.5:

build error gyp err! stack error: `make` failed exit code: 69 gyp err! stack     @ childprocess.onexit (/usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:270:23) gyp err! stack     @ emittwo (events.js:87:13) gyp err! stack     @ childprocess.emit (events.js:172:7) gyp err! stack     @ process.childprocess._handle.onexit (internal/child_process.js:200:12) gyp err! system darwin 14.5.0 gyp err! command "/usr/local/cellar/node/4.1.1/bin/node" "/bin/node-gyp.js" "rebuild" gyp err! cwd /node_modules/fsevents gyp err! node -v v4.1.1 gyp err! node-gyp -v v3.0.1 gyp err! not ok npm warn optional dep failed, continuing fsevents@0.3.8 

this resolve installing xcode 7. run update on xcode and, magically, works again.