2.3.0

sbt-assembly 2.3.0 is cross published to:

sbt Version	Published
1.x	✅
2.0.0-M2	✅

Note: Shading on sbt 2.0.0-M2 requires setting exportJars := false.

sbt 2.x migration

• Cross build to sbt 2.x by @eed3si9n in #533
• refactor: Uses new slash syntax by @xuwei-k in #531
• refactor: Update the types by @eed3si9n in #535

updates

• fix: Fixes assembly not creating parent directories by @Roiocam in #525
• fix: Throws error when a misconfigured assemblyOutputPath is detected by @hygt in #523
• fix: Fixes compililation error on JDK 23 by @xuwei-k in #530

behind the scene

• ci: Adds JDK 24 CI by @xuwei-k in #532

new contributors

• @hygt made their first contribution in #523
• @Roiocam made their first contribution in #525

Full Changelog: v2.2.0...v2.3.0

2.2.0

updates

• Update to jarjar-abrams-core 1.14.0 by @eed3si9n in #522
• Reduce memory usage by avoiding to buffer entry contents during MergeStrategy.deduplicate by @shuttie in #520

behind the scenes

• Fixes typo in readme by @SethTisue in #518
• Warn about parasitized über JARs in readme by @eed3si9n in #521

new contributors

• @shuttie made their first contribution in #520

Full Changelog: v2.1.5...v2.2.0

2.1.5

fixes

• Updates jarjar-abrams to 1.13.1, which fixes processing of classes built with Java 14 (ASM8) and 17 (ASM9) by @cdegroc in #512 / eed3si9n/jarjar-abrams#43
• Reproduces code for issue #479 by @xuwei-k in #514

behind the scene

• Updates JDK 22-ea setup by @eed3si9n in #510

new contributors

• @cdegroc made their first contribution in #512

Full Changelog: v2.1.4...v2.1.5

2.1.4

updates

• Updates to Jar Jar Abrams 1.13.0 by @eed3si9n in #509

behind the scene

• Removes unused scalatest dependency by @xuwei-k in #507
• Updates GitHub Actions by @eed3si9n in #508

Full Changelog: v2.1.3...v2.1.4

2.1.3

updates

• jarjar abrams 1.9.0 by @eed3si9n in #505

Full Changelog: v2.1.2...v2.1.3

2.1.2

updates

• Updates jarjar abrams to 1.8.3 by @eed3si9n in #504

behind the scene

• Updates README: Updates scala versions in test and README by @xuwei-k in #498
• Updates README: log4j2 plugin has been updated and re-released by @mpollmeier in #502

new contributors

• @mpollmeier made their first contribution in #502

Full Changelog: v2.1.1...v2.1.2

2.1.1

updates

• jarjar-abrams 1.8.2 by @eed3si9n in #494

Full Changelog: v2.1.0...v2.1.1

2.1.0

updates

• Adds Tags.limit(Assembly.assemblyTag, 1) by default to make assembly task exclusive @ingarabr in #485
• Fixes file concatenation merge rule by @dragisak in #482

new Contributors

• @ingarabr made their first contribution in #485
• @dragisak made their first contribution in #482

Full Changelog: v2.0.0...v2.1.0

2.0.0

In-memory processing

sbt-assembly 2.0.0 has been refactored to use in-memory processing of library entries, in contrast to its prior versions where library JAR files were unzipped to disk. This has positive performance implications, especially for large projects, machines with slow disks (i.e. spinning hard drives) or systems with slow file systems such as Windows Subsystem for Linux (WSL1) emulated file access.

This overhaul was contributed by Ben Reyes (@fnqista) in #464.

Breaking changes

• MergeStrategy.rename behavior was changed. Directories named LICENSE etc will no longer be renamed anymore. If these directories conflict with files named LICENSE etc the files will be renamed to include the assembly jar name (minus the .jar extension) instead.
• Fails *.class renames via MergeStrategy.rename, where it was a silent no-op previously.
• assemblyCacheUnzip setting was dropped.
• excludedFiles field was dropped from AssemblyOption.

Performance improvements

sbt-assembly 2.0.0 generally improves the performance compared to the the previous versions, however the effect of speedup may be dependent on the filesystem and hardware configuration. For example, a Play app that used to take 10s to assemble now assembles in 7s. On Windows, we expect more speedup.

In addition, a new setting called ThisBuild / assemblyRepeatableBuild is introduced:

ThisBuild / assemblyRepeatableBuild := false

The setting is set to true (repeatable) by default, but if set to false, sbt-assembly will parallelize JAR creation for an even faster performance. For instance, a Play app that used to take 10s assembled in 5s on Mac. Your mileage may vary.

CustomMergeStrategy.apply

sbt-assembly 2.0.0 introduces CustomMergeStrategy builder to construct custom merge strategies.

// same as discard
CustomMergeStrategy("custom-discard") { conflicts =>
  Right(Vector.empty)
}

Bug fixes

• Fixes the reported number of affected files
• Files that conflict with directories after the merge will now be printed as a clear error message to the user, instead of failing at runtime
• Fixes the caching directory to reflect the crossVersion, where previously, cross-builds (i.e. 2.12.8, 2.13.8) shared the same cache directory.
• Fixes Windows problems (#472) by @fnqista in #478
• Runs CI on Windows by @nightscape in #471
• Removes excessive "=" sign in launch script cmd by @DagoDragony in #468

New Contributors

• @fnqista made their first contribution in #464
• @DagoDragony made their first contribution in #468

Full Changelog: v1.2.0...v2.0.0

2.0.0-RC1

What's changed

sbt-assembly 2.0.0 has been refactored to use in-memory processing of library entries, in contrast to its prior versions where library JAR files were unzipped to disk. This has positive performance implications, especially for large projects, machines with slow disks (i.e. spinning hard drives) or systems with slow file systems such as Windows Subsystem for Linux (WSL1) emulated file access.

This overhaul was contributed by Ben Reyes (@fnqista) in #464.

Breaking changes

• MergeStrategy.rename behavior was changed. Directories named LICENSE etc will no longer be renamed anymore. If these directories conflict with files named LICENSE etc the files will be renamed to include the assembly jar name (minus the .jar extension) instead.
• Fails *.class renames via MergeStrategy.rename, where it was a silent no-op previously.
• assemblyCacheUnzip setting was dropped.
• excludedFiles field was dropped from AssemblyOption.

Performance improvements

sbt-assembly 2.0.0-RC1 generally improves the performance compared to the the previous versions, however the effect of speedup may be dependent on the filesystem and hardware configuration. For example, a Play app that used to take 10s to assemble now assembles in 7s. On Windows, we expect more speedup.

In addition, a new setting called ThisBuild / assemblyRepeatableBuild is introduced:

ThisBuild / assemblyRepeatableBuild := false

The setting is set to true (repeatable) by default, but if set to false, sbt-assembly will parallelize JAR creation for an even faster performance. For instance, a Play app that used to take 10s assembled in 5s on Mac. Your mileage may vary.

CustomMergeStrategy.apply

sbt-assembly 2.0.0 introduces CustomMergeStrategy builder to construct custom merge strategies.

// same as discard
CustomMergeStrategy("custom-discard") { conflicts =>
  Right(Vector.empty)
}

Bug fixes

• Fixes the reported number of affected files
• Files that conflict with directories after the merge will now be printed as a clear error message to the user, instead of failing at runtime
• Fixes the caching directory to reflect the crossVersion, where previously, cross-builds (i.e. 2.12.8, 2.13.8) shared the same cache directory.