from a fresh import of this example release tag mbed-os-5.1.2 there are hundreds of warnings for: This issue was found while testing ARMmbed/mbed-os-example-client copy of: https://github.com/ARMmbed/mbed-os-example-client/issues/77 [Warning] mbed_config.h@29,0: #47-D: incompatible redefinition of macro "UNITY_INCLUDE_CONFIG_H" (declared at line 28) in mbed_config.h, multiple defines are generated for this macro. // Macros # define UNITY_INCLUDE_CONFIG_H None // defined by library:utest # define UNITY_INCLUDE_CONFIG_H // defined by library:utest