Webjar causes OutOfMemoryError

[jimmy-rustles-vibes]

Not sure if this is expected or should be reported as a bug. The webjar causing this problem (uswds__uswds) has a lot of web resources (css, js, fonts, svgs, etc.). A webjar with few web resources (e.g. htmx.org) doesn't have this problem.

Steps to reproduce

1. Create a project
   quarkus create && cd code-with-quarkus

2. Add the webjar:

<dependency>
    <groupId>org.webjars.npm</groupId>
    <artifactId>uswds__uswds</artifactId>
    <version>3.13.0</version>
    <scope>runtime</scope>
</dependency>

3. Run the application
   quarkus dev

Console output

[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] 
[INFO] ---------------------< org.acme:code-with-quarkus >---------------------
[INFO] Building code-with-quarkus 1.0.0-SNAPSHOT
[INFO]   from pom.xml
[INFO] ------------------------------[ quarkus ]-------------------------------
[INFO] 
[INFO] --- quarkus:3.37.4:dev (default-cli) @ code-with-quarkus ---
[INFO] Invoking quarkus:3.37.4:generate-code (default-generate-code) @ code-with-quarkus
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  01:43 min
[INFO] Finished at: 2026-07-23T08:26:43-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Java heap space -> [Help 1]
java.lang.OutOfMemoryError: Java heap space
    at java.lang.StringBuilder.toString (StringBuilder.java:478)
    at io.quarkus.fs.util.rozip.ReadOnlyZipPath.buildNormalized (ReadOnlyZipPath.java:245)
    at io.quarkus.fs.util.rozip.ReadOnlyZipPath.normalize (ReadOnlyZipPath.java:209)
    at io.quarkus.fs.util.rozip.ReadOnlyZipFileSystemProvider.toEntryName (ReadOnlyZipFileSystemProvider.java:346)
    at io.quarkus.fs.util.rozip.ReadOnlyZipFileSystemProvider.newDirectoryStream (ReadOnlyZipFileSystemProvider.java:159)
    at java.nio.file.Files.newDirectoryStream (Files.java:445)
    at java.nio.file.FileTreeWalker.visit (FileTreeWalker.java:288)
    at java.nio.file.FileTreeWalker.next (FileTreeWalker.java:354)
    at java.nio.file.FileTreeIterator.fetchNextIfNeeded (FileTreeIterator.java:81)
    at java.nio.file.FileTreeIterator.hasNext (FileTreeIterator.java:101)
    at java.util.Spliterators$IteratorSpliterator.tryAdvance (Spliterators.java:1949)
    at java.util.stream.StreamSpliterators$WrappingSpliterator.lambda$initPartialTraversalState$0 (StreamSpliterators.java:297)
    at java.util.stream.StreamSpliterators$WrappingSpliterator$$Lambda/0x00000000651f7ec8.getAsBoolean (Unknown Source)
    at java.util.stream.StreamSpliterators$AbstractWrappingSpliterator.fillBuffer (StreamSpliterators.java:206)
    at java.util.stream.StreamSpliterators$AbstractWrappingSpliterator.doAdvance (StreamSpliterators.java:169)
    at java.util.stream.StreamSpliterators$WrappingSpliterator.tryAdvance (StreamSpliterators.java:303)
    at java.util.Spliterators$1Adapter.hasNext (Spliterators.java:669)
    at io.quarkus.paths.PathTreeVisit.walk (PathTreeVisit.java:59)
    at io.quarkus.paths.OpenContainerPathTree.walk (OpenContainerPathTree.java:76)
    at io.quarkus.paths.ArchivePathTree$OpenArchivePathTree.walk (ArchivePathTree.java:354)
    at io.quarkus.paths.PathTree.getResourceNames (PathTree.java:129)
    at io.quarkus.paths.ArchivePathTree$OpenArchivePathTree.getResourceNames (ArchivePathTree.java:384)
    at io.quarkus.paths.SharedArchivePathTree$CallerOpenPathTree.getResourceNames (SharedArchivePathTree.java:206)
    at io.quarkus.bootstrap.classloading.PathTreeClassPathElement.getProvidedResources (PathTreeClassPathElement.java:156)
    at io.quarkus.bootstrap.classloading.ClassPathResourceIndex$Builder.scanClassPathElement (ClassPathResourceIndex.java:209)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.getClassPathResourceIndex (QuarkusClassLoader.java:383)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass (QuarkusClassLoader.java:589)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass (QuarkusClassLoader.java:571)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass (QuarkusClassLoader.java:624)
    at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass (QuarkusClassLoader.java:571)
    at io.quarkus.maven.GenerateCodeMojo.generateCode (GenerateCodeMojo.java:93)
    at io.quarkus.maven.GenerateCodeMojo.doExecute (GenerateCodeMojo.java:65)
[ERROR] 
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/OutOfMemoryError

[holly-cummins]

Is there the same issue with mvnpm, such as https://mvnpm.org/package/org.mvnpm.at.types:uswds__uswds?

[jimmy-rustles-vibes]

That jar is for TypeScript definitions, but I found the mvnpm equivalent here: org.mvnpm.at.uswds:uswds.
It doesn't have the same issue. Don't know why, but I'll take it.

[holly-cummins]

Oh, thanks for finding the better link than I did. Glad it helps!

[phillip-kruger]

It's probably just the size of the jar. We are typically smaller.

[jimmy-rustles-vibes]

The Java process eventually gives out at ~17 GB on my machine when normally sits around <1 GB. I'm not familiar with what exactly Quarkus does during build time, but it looks like this specific webjar managed to break that process.