Sentry unable to load source maps from artifacts

Sentry version: Sentry 20.11.1 14468076 (on-premise)
Operating system:

  • Operating System: Debian GNU/Linux 9 (stretch)
  • Kernel: Linux version 4.9.0-14-amd64
  • Architecture: x86-64

Sentry does not use source maps uploaded in artifacts. I’ve been trying to find out the reason for almost two days, but without success. My configuration seems to be all right.

Webpack plugin

Source maps are uploaded with Webpack plugin:

        new SentryWebpackPlugin({
            urlPrefix: "~/ng-maps/",
            url: "",
            include: "dist",

Source maps are not available online

After the source maps are uploaded to Sentry, we remove them so that they are not available online.

Release exists

When I check Sentry, there is a new release ow-5.2.1-20201120-343-gd58898f0c4f8

Artifacts are uploaded

When I check the artifacts in the release ow-5.2.1-20201120-343-gd58898f0c4f8, they are successfully uploaded:

For example, there is:


The sourceMappingURL is present

The following line is at the bottom of


The artifact ~/ng-maps/js/12.e13162ee90fd43b4654a.js in Sentry has the same line at the bottom.

The source map file is valid

When I check the source map, I can see sourcesContent inside. The source map file is valid because Sentry loads it correctly when it is available online.

The source map file is small enough

$ du -bh 12.e13162ee90fd43b4654a.js*
48K	12.e13162ee90fd43b4654a.js

The source map file is not gzipped

The source map file is not gzipped:

$ file 12.e13162ee90fd43b4654a.js*
12.e13162ee90fd43b4654a.js:     exported SGML document, ASCII text, with very long lines JSON data

Issue and event JSON

When I simulate an exception in the application, I can see it as a new issue in Sentry:

Here is the event JSON. The abs_path contains “online” URL, but if I understand it correctly, it should pick the file from artifacts just by replacing the domain with ~.

The docker volumes are shared

The Sentry is installed in docker the common way (I followed the official guide and ran I checked volumes of sentry_onpremise_cron_1, sentry_onpremise_web_1 and sentry_onpremise_worker_1. All point to the same directory on the filesystem /var/lib/docker/volumes/sentry-data/_data.

I have no idea what else I should check. I’m almost sure everything is set up correctly. But apparently I missed out something.

Does anyone have a clue what might be a problem? Should I upgrade something? Or is there a helpful log file that I should look at?

Does the configuration presented above look reasonable or did I miss something?

Thanks in advance for help! :slight_smile:

Hey there. In your first post you say that sourceMappingURL is pointing to a specific path:


However, in the JSON provided, you can definitely tell that it’s not the case:

All abs_path in frames are pointing to external sources, like which is most likely the issue.

Because every sourceMappingURL is using / as the first character, it’s always trying to map using the domain where the error happened.

However, without access to the event page, it’s very difficult to tell what went wrong, and from what I see you are using on-premise, which also makes it slightly more complex, as it adds another layer where it could break.

Thank you for your reply. I checked our installation again and there is indeed the following line in the 12.e13162ee90fd43b4654a.js file.


But "post_context" somehow contains "/ng-maps/js/" when I emit an error.

I cannot provide you access to the server, but I will investigate why the abs_path and post_context does not look correctly.

Could you please tell me, what content is expected in "filename", "abs_path" and "post_context"? Should there be something like this?

"abs_path": "~/ng-maps/js/12.e13162ee90fd43b4654a.js",
"filename": "~/ng-maps/js/12.e13162ee90fd43b4654a.js",
"post_context": [
  "//# sourceMappingURL=12.e13162ee90fd43b4654a.js"

Maybe, I could rewrite frames and “fix” them with Pluggable Integrations for Node.js | Sentry Documentation

I think the best way to understand the whole flow is go through the code itself:

You can also take a look at fetch_sourcemap => fetch_file => fetch_release_file pipeline, as this is how files are fetched for the sourcemaps resolution.

If this won’t help, you can take a look at Pluggable Integrations for JavaScript | Sentry Documentation // sentry-javascript/rewriteframes.ts at 53e1df949cfa9ba0b4da6707f08246a8b2d2dee6 · getsentry/sentry-javascript · GitHub and try to use it instead, as it should give you a complete control over exception file paths.

Thank you for the advice. I will check the source code and debug it if necessary.