User script code that has been developed for execution in a host application can be remapped to debuggable script code, based on explicit debugging gestures, allowing for appropriate debugging coverage for the code while mitigating execution (in)efficiency issues. Capabilities of a virtual machine used for a host application can be determined, and the user script code can be instrumented with guards for detecting explicit debugging gestures based on capabilities of the virtual machine. The instrumented user script code can be executed in a runtime environment, for example, by a just-in-time compilation service. If an explicit debugging gesture is detected, a function where the gesture was detected can be transformed into debuggable script code, in one embodiment, based on the debuggable gesture detected.