Add dependency on libm as required by #93

Jan Breuer

2017-08-16 4f960d20c76cb67e206a62f0e6c7608d75693ddc

 libscpi/src/error.c

@@ -45,7 +45,7 @@
#if USE_DEVICE_DEPENDENT_ERROR_INFORMATION
#define SCPI_ERROR_SETVAL(e, c, i) do { (e)->error_code = (c); (e)->device_dependent_info = (i); } while(0)
#else
#define SCPI_ERROR_SETVAL(e, c, i) do { (e)->error_code = (c); } while(0)
#define SCPI_ERROR_SETVAL(e, c, i) do { (e)->error_code = (c); (void)(i);} while(0)
#endif

/**