[BUG] Debugging experience is very poor

[resynth1943]

Describe the bug

When Rollup encounters a runtime error, it leaves you with very little to go on -- aside from a stack trace, containing mangled function names and hard-to-reach line numbers.

This doesn't really help:

[resynth@synthcave synth-di]$ time deno run --unstable --allow-read --allow-write --allow-env --allow-net https://deno.land/x/[email protected]/cli.ts --config ./build/base.config.ts
error: Uncaught (in promise) TypeError: Cannot read property 'split' of undefined
    at Ve (https://unpkg.com/[email protected]/dist/es/rollup.browser.js:11:31514)
    at Ra (https://unpkg.com/[email protected]/dist/es/rollup.browser.js:11:318386)
    at async Ua.loadEntryModule (https://unpkg.com/[email protected]/dist/es/rollup.browser.js:11:327081)
    at async Promise.all (index 0)

To Reproduce
Steps to reproduce the behavior:

1. Encounter a runtime error in Rollup
2. See error

Expected behavior

You get an un-minifed error.
The Rollup module you're importing does not come with a source map, btw.

[resynth1943]

I see two ways to fix this:

• stop including the minified version of Rollup, and use the clear one instead
• encourage Rollup developers to include a source-map in the bundle (I'm not sure if Deno supports source maps?)

[probins]

this is surely an issue for Rollup - it ought to be simple for them to add a sourcemap to the browser output file (I'm not sure how much the browser file is actually used).

Deno supports V8 Inspector (I often use the inspect-brk option), though I think you have to use deno run - I don't think it works as an option on the installed denopack.

[resynth1943]

It may be a Rollup issue, yes. Good point.

[cmorten]

FYI I have raised an issue for the particular error you reference above rollup/rollup#3934 and a PR to fix rollup/rollup#3935 in the Rollup project. Doesn’t help with the debugging aspect of this issue, but may provide some more context what the error is, why it occurs and hopefully a path forward towards fixing it.