A module has no debugger in the place it runs. The way in is printing from inside, and printing from inside is a decision about what the module is allowed to say.
About 1 min of reading
Resolve an offset
Write the trap offset
Before you run it, say out loud what it will print. Then open the answer.
Resolve with the map
Before you run it, say out loud what it will print. Then open the answer.
Stamp the build used
Before you run it, say out loud what it will print. Then open the answer.
The map is the only link between an offset and a name. A shipped module without a map is a module that cannot be read.
The buffer is copied per crossing. Debug output is a cost, and a cost that ships is a cost that is measured.
The module writes to a buffer and the host reads it. The buffer is the channel, and the channel has a size.
A trap gives an offset. The offset plus the symbol map is a line, and the map is a build flag.
Optimisation removes the values that were printed. Debugging is done on a build that is not shipped.
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.