Get stacktrace information in release build of DevTools

[elliette]

Opening a bug to track work around @sigmundch's suggestions here:

• Compile release build of DevTools with default dart2js optimizations  #7335 (comment)
• Compile release build of DevTools with default dart2js optimizations  #7335 (comment)

@sigmundch - if we go with option 1, is there a way to specify --no-minify for Flutter web apps? flutter/flutter#62259 indicates the only way is to use the profile build.

@kenzieschmoll for option 2, we would need to update the release process to ship DevTools sourcemap file as well. Wdyt of that approach?

Thanks!

[kenzieschmoll]

If option 2 (shipping the sourcemap file) is the recommended approach for shipping a minified app with meaningful stack traces from production builds, I think this sounds like a good option. @bkonyi @sortie do you see any issues with including a sourcemap file with our build that is uploaded to CIPD and included in the Dart SDK?

[sigmundch]

Re option 1: correct, I believe today the only way is to use --profile unless we add additional flags to the flutter tool or allow specifying arbitrary dart2js flags (request in flutter/flutter#99015). Good news is that today --profile seems to only pass --no-minify on top of what --release has, so it happens to match the flags we want.

Re option 2: note that the deobfuscation process will be done offline, so access to the sourcemap is not needed while the app is running. As such, the sourcemap file doesn't need to be shipped with the app, it just needs to be built and archived in a way that can be retrieved easily for each individual released version of the app. Then, when a report comes in (either through user reporting or crash analytics, if supported), you can retrieve the .map file that corresponds to the app that produced the crash.

Today we have a .zip created in this repo for each release tag, if that zip included the compiled .js and .map file, that would do. It would also work if we upload the .map file to CIPD, but we can exclude it when we create the Dart SDK binary.

[sortie]

@kenzieschmoll You can include any files you wish in the devtools_shared and devtools_app/build/web directories per the recipe https://dart.googlesource.com/recipes/+/refs/heads/main/recipes/roller/devtools.py#78

I have no opinion on the technical aspects of a source map, don't know the tech, I just package it :)

[bkonyi]

If option 2 (shipping the sourcemap file) is the recommended approach for shipping a minified app with meaningful stack traces from production builds, I think this sounds like a good option. @bkonyi @sortie do you see any issues with including a sourcemap file with our build that is uploaded to CIPD and included in the Dart SDK?

I don't think it'd be a problem, but we should always keep SDK size in mind when adding new artifacts. How big is the source map?

[sigmundch]

... we should always keep SDK size in mind when adding new artifacts. How big is the source map?

FWIW, this is why I was highlighting above that shipping it with the SDK is optional. It is enough to build it and save it in CIPD so we can retrieve it later for deobfsucation, we just need to have a reliable way to find the .map file corresponding to a release.

[bkonyi]

... we should always keep SDK size in mind when adding new artifacts. How big is the source map?

FWIW, this is why I was highlighting above that shipping it with the SDK is optional. It is enough to build it and save it in CIPD so we can retrieve it later for deobfsucation, we just need to have a reliable way to find the .map file corresponding to a release.

Oops, I clearly didn't read the entire thread... :) that makes sense. If we package it with the CIPD release of DevTools, it shouldn't be too hard to find it if we know the Dart SDK version.

[sigmundch]

Oops, I clearly didn't read the entire thread... :)

haha. I also didn't give a clear rationale on my earlier post, so I was just connecting the two thoughts 😄