Desired Behavior

Unless inhibited, Dune currently uses a BUILD_PATH_PREFIX_MAP to map build-time absolute paths to reproducible paths, starting with /workspace_root. The result is that the ocamldebug debugger cannot find the sources.

This is a request for Dune to produce a feature to enable starting ocamldebug with a BUILD_PATH_PREFIX_MAP that will perform the logical inverse of the other mapping, so that /workspace_root is mapped in a way to enable the debugger to find the sources, and perhaps other installed artifacts. (ocamldebug is in the process of being modified to honor BUILD_PATH_PREFIX_MAP, see ocaml/ocaml#12126)

Example

One possible interface example is to just add an --ocamldebug option to dune exec. So a command like

dune exec --ocamldebug ./bin/main.bc

would start to execute that program in the ocamldebug debugger.

I'm currently experimenting with implementing such a feature.