This happened seemingly randomly during development. When trying to run npm start or react-native run-ios, I get the following error:
Failed to build DependencyGraph: @providesModule naming collision:
Duplicate module name: react-native-vector-icons
Paths: /Users/chandlervdw/Repos/Relay/mobile/node_modules/react-native/local-cli/rnpm/core/test/fixtures/files/package.json collides with /Users/chandlervdw/Repos/Relay/mobile/node_modules/react-native/Libraries/Animated/release/package.json
This error is caused by a @providesModule declaration with the same name accross two different files.
Error: @providesModule naming collision:
Duplicate module name: react-native-vector-icons
Paths: /Users/chandlervdw/Repos/Relay/mobile/node_modules/react-native/local-cli/rnpm/core/test/fixtures/files/package.json collides with /Users/chandlervdw/Repos/Relay/mobile/node_modules/react-native/Libraries/Animated/release/package.json
This error is caused by a @providesModule declaration with the same name accross two different files.
at HasteMap._updateHasteMap (/Users/chandlervdw/Repos/Relay/mobile/node_modules/node-haste/lib/DependencyGraph/HasteMap.js:162:15)
at /Users/chandlervdw/Repos/Relay/mobile/node_modules/node-haste/lib/DependencyGraph/HasteMap.js:140:25
Strangely, /Users/chandlervdw/Repos/Relay/mobile/node_modules/react-native/local-cli/rnpm/core/test/fixtures/files/package.json actually does list react-native-vector-icons as the name for the module???
If I delete that file, the error no longer happens but the packager gets stuck at 93% and complains about a completely irrelevent library not being found.
I blew away my repo and even reinstalled everything, including npm, rnpm, and even upgrading node. I'm running the same versions of everything as my teammates, who are able to run the packager without issues.
Posting this as an answer just in case anybody else has this issue in future.
Running npm start with sudo permissions grants the correct privileges when nodes package manager is running the initial build phase. This only seems to happen if the shell/user that you are running from has restricted privileges. Force escalating privileges to sudo gives the package manager full control to complete the build.