react native watchmanResponse unable to resolve root - react-native

Question

There is an error when I build my react-native project with the version 0.20.0:
Looking for JS files in
/Users/rockyl/WorkSpaces/react-native/TinySNS
[13:55:06] <START> Building Dependency Graph
[13:55:06] <START> Crawling File System
[13:55:06] <START> Loading bundles layout
[13:55:06] <END> Loading bundles layout (1ms)
[Hot Module Replacement] Server listening on /hot
React packager ready.
ERROR unable to resolve root /Users/rockyl/WorkSpaces/react-native/TinySNS: failed to opendir(/Users/rockyl/WorkSpaces/react-native/TinySNS): No such file or directory
{"watchmanResponse":{"version":"4.4.0","error":"unable to resolve root /Users/rockyl/WorkSpaces/react-native/TinySNS: failed to opendir(/Users/rockyl/WorkSpaces/react-native/TinySNS): No such file or directory"}}
Error: unable to resolve root /Users/rockyl/WorkSpaces/react-native/TinySNS: failed to opendir(/Users/rockyl/WorkSpaces/react-native/TinySNS): No such file or directory
at BunserBuf.<anonymous> (/Users/rockyl/WorkSpaces/react-native/TinySNS/node_modules/react-native/node_modules/sane/node_modules/fb-watchman/index.js:95:23)
at emitOne (events.js:77:13)
at BunserBuf.emit (events.js:169:7)
at BunserBuf.process (/Users/rockyl/WorkSpaces/react-native/TinySNS/node_modules/react-native/node_modules/bser/index.js:289:10)
at /Users/rockyl/WorkSpaces/react-native/TinySNS/node_modules/react-native/node_modules/bser/index.js:244:12
at doNTCallback0 (node.js:419:9)
at process._tickCallback (node.js:348:13)
See http://facebook.github.io/react-native/docs/troubleshooting.html
for common problems and solutions.
here is the logs:
and here is the real-time logs:
But the root path truly exists.

Answer 1

Thanks for posting those logs; what's happening here is an issue with the casing of the WorkSpaces directory in that path that is being watched. There's some complicated background to this that results in watchman needing to know the exact casing of the file names so that we can report on case-change-only-renames.
The TL;DR is that you should either ask React Native to watch the path using Workspaces as the directory name, or rename the directory so that it is actually WorkSpaces (in other words, make sure that the path you're asking for exactly matches that of the filesystem).
There are a couple of watchman bugs here that I'll work on fixing in the meantime:
We should canonicalize this path using our strict canon at the earlier stage in watching (should make this use case "just work")
We should surface this error with this explanation when such a mismatch occurs

Answer 2

In short: Just rename the containing folder where your project is located to workspaces (All in lowercase), an example here: