You can try to change the library from EWL to newlib when you create project. you also can change this setting after you create project. PATH: Project right click --> Propertites --> C/C++ Build --> Settings --> Target Processor --> Libraries support.
I don't know the root cause, but i meet the same problem and solved by changing the library setting.
could you please share more details? Description that you added "some code" is not enough to provide any support. It will be best, if you can share some simple example, which demonstrates your problem. If this is not possible, please provide as much details as possible.