hi there,
Hiya, sorry you are having trouble with your build.
This Common Issue contains a ton of useful debugging tips that can likely help you solve your problem 
We also recommend trying to search the forums with the build error you encountered - it’s likely your question was already asked by someone else!
If you are still having problems, please provide as much information as you can on what you have already tried, a full build log, what your build settings are, your package.json, etc. Thanks!