Error and Stacktrace not matching - even with proper sourcemaps uploaded

[arnaudambro]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Self-hosted/on-premise

Which SDK are you using?

@sentry/react

SDK Version

7.69.0

Framework Version

18.2.0

Link to Sentry event

https://sentry.fabrique.social.gouv.fr/organizations/incubateur/issues/114896/events/ce7e6016a8134227996c9ca4aebb83ac/

SDK Setup

https://github.com/SocialGouv/mano/blob/main/dashboard/src/app.js#L61

import { createBrowserHistory } from 'history';
import * as Sentry from '@sentry/react';
import { BrowserTracing } from '@sentry/tracing';
const history = createBrowserHistory();

Sentry.init({
  dsn: MY_DSN,
  environment: 'dashboard',
  release: PACKAGE_JSON_VERSION, // 1.2.3
  integrations: [
    new BrowserTracing({
      routingInstrumentation: Sentry.reactRouterV5Instrumentation(history),
    }),
  ],
  
  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for performance monitoring.
  // We recommend adjusting this value in production
  tracesSampleRate: 1.0,
  ignoreErrors: [
    'Network request failed',
    'Failed to fetch',
    'NetworkError',
    // ???
    'withrealtime/messaging',
    // This error seems to happen only in firefox and to be ignorable.
    // The "fetch" failed because user has navigated.
    // Since other browsers don't have this problem, we don't care about it,
    // it may be a false positive.
    'AbortError: The operation was aborted',
  ],
});

https://github.com/SocialGouv/mano/blob/main/dashboard/Dockerfile#L22

FROM node:14-alpine as builder

RUN apk add --no-cache gcc autoconf automake build-base libpng-dev nasm

WORKDIR /app

RUN chown node:node /app

COPY dashboard/package.json .
COPY dashboard/yarn.lock .

RUN yarn --frozen-lockfile

COPY dashboard/. .

ENV NODE_ENV=production

RUN --mount=type=secret,id=sentry_auth_token \
    yarn build; \
    if [ -f "/run/secrets/sentry_auth_token" ]; then \
        export SENTRY_AUTH_TOKEN=$(cat /run/secrets/sentry_auth_token); \
        yarn sentry:sourcemaps; \
    fi


FROM ghcr.io/socialgouv/docker/nginx4spa:7.0.1

COPY --from=builder /app/build /usr/share/nginx/html

https://github.com/SocialGouv/mano/blob/main/dashboard/package.json#L80

{
  "scripts": {
    "sentry:sourcemaps": "sentry-cli sourcemaps inject --org incubateur --project mano ./build && sentry-cli --url https://sentry.fabrique.social.gouv.fr/ sourcemaps upload --org incubateur --project mano ./build --log-level=debug  --release $npm_package_version"
  }
}

Steps to Reproduce

Here is what I see

Settings about "scrape missing JavaScript"

Seen in #7250 - but still the same after changing the setting - at least for old issues - should I wait for new issues ?

Proof of my sourcemaps :)

Expected Result

person is undefined ?

Actual Result

s is undefined

[Lms24]

Hi @arnaudambro thanks for writing in and for the excellent issue description!

As far as I can tell the screenshots and your description show expected behaviour. Our symbolication approach is only able to resolve the source code in and around the location of the error (as seen in the screenshot). However it cannot un-minify the variable name mentioned in the error message. It would be very hard to reliably match the minified symbols with their original names, given that there's not a lot of context to work with.

While I agree though that it'd be a cool feature to have, I'm going to close this issue because at the moment we cannot do a lot about this. Thanks thought for bringing it up!

[arnaudambro]

alright, thanks a lot @Lms24 for your answer

so it means that the sourcemaps still make sure that the bug is located where sentry shows it ?

meaning that, in my example, even if s is not in my sourcecode id={person.user}, the bug IS 100% CERTAIN located at the line id={person.user}, and it's just a matter of me guessing what s is in that line ?

[Lms24]

I can't guarantee you 100% certainty because sometimes (depending on framework, bundler, bundler plugins, etc) source maps are messed up or don't contain enough information. However, we're improving source maps and stack trace symbolication to increase the quality as much as we can.

I'd say it's pretty unlikely that the completely wrong line of code is highlighted as the error-causing line. Just can't guarantee it with 100%. In case you encounter errors where you have the feeling that it might be the wrong line, you can always look at the original, raw stack trace to further verify where this is happening in your minified code.