Index Sourcemaps not supported in `sourcemaps inject`

[stigi]

CLI Version

2.43.0

Operating System and Architecture

• macOS (arm64)
• macOS (x86_64)
• Linux (i686)
• Linux (x86_64)
• Linux (armv7)
• Linux (aarch64)
• Windows (i686)
• Windows (x86_64)

Operating System Version

macOS 15.4

Link to reproduction repository

https://github.com/stigi/sentry-vs-index-source-maps

CLI Command

sentry-cli sourcemaps inject ...

Exact Reproduction Steps

1. Clone the repro repo
2. Run npm install
3. Run npm sentry-cli sourcemaps inject dist-example

Context:

• Those sourcemaps are produced from ClojureScript by compiling it with ShadowCLJS.
• The sourcemaps are index source maps with sections
• We used sentry-cli version 2.18.1, which supported those kind of sourcemaps and added debug_id to the .map file successfully. We also use those source maps successfully after uploading to Sentry.
• The first CLI version where we saw this break is 2.19.0
• rust-sourcemaps seems to support index sourcemaps as SourceMapIndex, but they do not have a debug_id attribute, and seem less fully implemented

Possible workarounds:

• The community mentioned using flatten-source-map to work around this, by flattening the sections into a single mappings string. I didn't try that myself yet though.

Thanks

Expected Results

The sourcemap and JS files are injected with a sentry debug id.

Actual Results

An incompatible sourcemap format error is produced:

> shadow-maps@0.0.1 demo:example
> sentry-cli sourcemaps inject dist-example

> Searching dist-example
> Found 2 files
> Analyzing 2 sources
> Analyzing completed in 0.001s
> Injecting debug ids
error: Invalid sourcemap at dist-example/demo.js.map

Caused by:
    encountered incompatible sourcemap format

Add --log-level=[info|debug] or export SENTRY_LOG_LEVEL=[info|debug] to see more output.
Please attach the full debug log to all bug reports.

Logs

  INFO    2025-04-11 19:21:27.913205 +02:00 Loaded config from /Users/ullrich/.sentryclirc
  DEBUG   2025-04-11 19:21:27.913576 +02:00 sentry-cli version: 2.43.0, platform: "darwin", architecture: "arm64"
  INFO    2025-04-11 19:21:27.914432 +02:00 sentry-cli was invoked with the following command line: "/Users/ullrich/tmp/shadow-maps/node_modules/@sentry/cli-darwin/bin/sentry-cli" "sourcemaps" "inject" "--log-level=debug" "dist-example"
> Searching dist-example
  DEBUG   2025-04-11 19:21:27.915325 +02:00 built glob set; 0 literals, 0 basenames, 0 extensions, 0 prefixes, 0 suffixes, 4 required extensions, 0 regexes  (from globset)
  DEBUG   2025-04-11 19:21:27.915949 +02:00 glob converted to regex: Glob { glob: "**/*~", re: "(?-u)^(?:/?|.*/)[^/]*\\~$", opts: GlobOptions { case_insensitive: false, literal_separator: true, backslash_escape: true, empty_alternates: false }, tokens: Tokens([RecursivePrefix, ZeroOrMore, Literal('~')]) }  (from globset)
  DEBUG   2025-04-11 19:21:27.915981 +02:00 built glob set; 0 literals, 1 basenames, 1 extensions, 0 prefixes, 0 suffixes, 0 required extensions, 1 regexes  (from globset)
  DEBUG   2025-04-11 19:21:27.916245 +02:00 ignoring dist-example/manifest.edn: Ignore(IgnoreMatch(Types(Glob(UnmatchedIgnore))))  (from ignore)
  DEBUG   2025-04-11 19:21:27.916281 +02:00 whitelisting dist-example/demo.js.map: Whitelist(IgnoreMatch(Types(Glob(Matched { def: FileTypeDef { name: "map", globs: ["*.map"] } }))))  (from ignore)
  INFO    2025-04-11 19:21:27.916314 +02:00 found: dist-example/demo.js.map (925466 bytes)
  DEBUG   2025-04-11 19:21:27.916692 +02:00 ignoring dist-example/.DS_Store: Ignore(IgnoreMatch(Types(Glob(UnmatchedIgnore))))  (from ignore)
  DEBUG   2025-04-11 19:21:27.916730 +02:00 whitelisting dist-example/demo.js: Whitelist(IgnoreMatch(Types(Glob(Matched { def: FileTypeDef { name: "js", globs: ["*.js"] } }))))  (from ignore)
  INFO    2025-04-11 19:21:27.916762 +02:00 found: dist-example/demo.js (96417 bytes)
> Found 2 files
> Analyzing 2 sources
> Analyzing completed in 0.002s
> Injecting debug ids
error: Invalid sourcemap at dist-example/demo.js.map

Caused by:
    encountered incompatible sourcemap format
  INFO    2025-04-11 19:21:27.928144 +02:00 Skipping update nagger update check

[tsiepe]

Hi @stigi ,

Thanks for opening this issue. I am experiencing the exact same problem, only that it's happening on my Ubuntu 22.04 LTS (x86_64) box.
However, as opposed to you, I did try to use the flatten-source-map node module but to no avail because in my case the source map is already 33MB in size and the RAM on my machine (32GB) was not enough. So, it got killed by the OS OOM killer.
Found other approaches to deal with the problem on Slack here https://clojurians.slack.com/archives/C6N245JGG/p1650879241997799. But they didn't seem to work.

That said I do think that for much smaller source maps the flatten-source-map approach will probably work.

I should probably add that this was a shadow-cljs release build that produced the giant source map.
If you don't do a release build and just take the source maps generated in the course of a normal dev compile then those will work with Sentry - I tried. But, obviously, that's not much use because we don't have the habit of deploying a dev build to production.

[szokeasaurusrex]

Hi @stigi and @tsiepe, thank you for raising this bug. I will investigate and let you know once I have more information to share

[szokeasaurusrex]

It indeed looks like we do not support indexed source maps. I am unsure why this stopped working from 2.18.1 to 2.19.0, but since sentry-cli sourcemaps inject was only made public in 2.19.0 (by unhiding it from the --help), we are going to treat this as a feature request.

That said, we are going to prioritize working on this issue. I'll update you once there is an ETA