The code is included on a per-package basis and enabled at runtime by an environment variable. Tracing All API calls made by an application can be displayed and include formal argument names and actual values and the function return value. This code is also conditionally included at compile time and enabled at runtime. By default any API function that fails will print an error stack to the standard error stream. Error detected in thread 0.
Back trace follows.
The library designers have made every attempt to handle error conditions gracefully but an invariant condition assertion may fail in certain cases. IOT Trap, core dumped. The switch can be followed by an equal sign and a comma-separated list of package names or else a default list is used. In addition to including the code at compile time the application must enable each package at runtime. The word all refers to all packages.