The C/C++ ecosystem has really been dragging down the popular expectation of what debugging (and at what level) is possible. They are uniquely bad in breaking p

The C/C++ ecosystem has really been dragging down the popular expectation of what debugging (and at what level) is possible. They are uniquely bad in breaking programmers' ability to understand what their programs do, with debugging being an essential part of that. JVMs move heaven and Earth to make optimization not observable and support the JVMTI, upon which debuggers are built. They are required to materialize a bytecode-level view of execution state upon demand, just as CPUs are required to materialize a machine-level view of execution state. As a result, any source debugger written against what is available at the bytecode level will work without needing to see through the abstractions.