Coursier Files

Highlights

This release mainly fixes regressions in 2.1.25, and makes downloads more resilient against transient network failures or overloaded servers.

• coursier.jar and the thin coursier launcher work again. In 2.1.25, these launchers bundled or pulled a Scala 2.13 cats-free next to the Scala 3-built CLI, so every resolution command (fetch, resolve, launch, …) failed with NoSuchMethodError: cats.implicits$.catsStdInstancesForList(). The stray 2.13 dependency is now gone. CI now also builds and tests JAR launchers, and rejects class paths that mix Scala binary versions. Fixes [#3865]. (#3879)
• No more duplicate conflicts. Since 2.1.25, a dependency declared as explicitly non-optional (optional0 = Some(false), as sbt does) and the same dependency with no optional flag were treated as two dependencies. That duplicated entries in minDependencies and in coursier.graph.Conflict(…), which broke sbt eviction warnings, for example. They are now normalized. Fixes [#3861]. (#3878)
• The Scala 3 artifacts target Scala 3.3 LTS. In 2.1.25 they were compiled with Scala 3.9.0, so only projects on 3.9 could use them. They are now built with 3.3.8, which makes them usable from any Scala 3.3+ project. (#3856)

Downloads and cache

• HTTP errors are retried with curl-style backoff. The server responses that curl's --retry retries are now retried too: 408, 500, 502, 503, 504, and Cloudflare's 522/524. The first retry waits 1 second, and the wait doubles each time, up to 10 minutes. A Retry-After header on any of those responses is honoured, not only on a 503. Other 5xx responses, such as 501, fail right away. Connection errors, timeouts, and SSL errors keep their short backoff (10 ms, doubling, up to 20 s). The new coursier.http-retry-backoff-initial-delay and coursier.http-retry-backoff-max-delay properties tune this. See the retries documentation. (#3884)
• The CLI retries downloads by default. --retry-count used to default to 1, so the CLI made a single attempt even when the cache would have retried. It now uses the cache's default (5 attempts, or the coursier.exception-retry Java property). Its help message also says that it covers network and server errors, not just checksum errors. (#3883)
• Cache servers are used automatically. When COURSIER_CACHE_SERVER points at a cache server, any FileCache using the default cache location now goes through that server. Before, only the default cache did. Local file: URLs are still read directly. The server also honours the client's cache policies and TTL. (#3887)
• Local archives are left alone. The archive cache no longer writes integrity files next to local archives that stay outside the cache (file: URLs), and no longer deletes them when they are corrupted. (#3885)

CLI and installation

• cs update now shows versions, e.g. Updated scalafmt (3.9.5 -> 3.9.6). (#3889)
• The Homebrew formula no longer depends on openjdk. That formula's java was on the PATH and shadowed the JVMs managed by coursier, so java and cs java could disagree. The native cs launcher doesn't need a JVM. The JAR-based coursier launcher uses the JVM from JAVA_HOME or the PATH, which cs setup can install. Shell completions now refer to cs. Fixes [#3763]. (#3886)

Library changes

• Scala 3 compiler crashes fixed. Some GraalVM-only classes carry annotations that reference GraalVM classes users don't have on their class path. When one of those classes sat in a package user code looks up, the Scala 3 compiler could crash. They now live in dedicated packages:
• coursier.exec.Graalvm* moved to coursier.exec.graalvm.
• The deprecated, unused coursier.jvm.GraalvmErrnoExtras and coursier.jvm.GraalvmUnistdExtras were removed.
• coursier.cache.internal.SigWinchNativeWindows moved to coursier.cache.internal.graalvm.

These are native-image internals, but they are binary-incompatible changes. (#3857, [#3862])

• Future lazy vals in the Scala 3 artifacts. They are compiled with -Yfuture-lazy-vals, the lazy val implementation that became the default in Scala 3.8 and works on JDK 25+. (#3866)
• Separate jsoniter-scala versions. The Scala 3 modules now use jsoniter-scala 2.41.0. The Scala 2 modules stay on 2.13.8, the last release with Java 8 class files. (#3855, [#3877])
• Scala.js artifacts are Scala 3 only. The _sjs1_2.13 artifacts are no longer published. (#3854)

Publishing

• Artifacts, snapshots included, are now also published to GitHub Packages. Sonatype Central remains the main repository. (#3881)

Build and release tooling

• Skip successfully uploaded release assets when re-running uploads (#3860)
• Resolve paths when smoke-testing JAR launchers (#3890)
• Use Mill's built-in Sonatype Central publisher, and serialize publishing jobs (#3891)
• Update Mill to 2.0.0-M2 (#3880)
• Avoid compilation when evaluating BSP workspace/buildTargets (#3888)
• Update cs.sh to 2.1.25 (#3859)
• Update the cs version building the Linux launchers to 2.1.25 (#3858)

Dependency updates

• Update dependency to 0.3.3 by @scala-steward (#3873)
• Update config_3 to 1.17.1 by @scala-steward (#3875)
• Update svm to 25.0.4.1.1 by @scala-steward (#3874)
• Update scalafix-core to 0.14.9 by @scala-steward (#3870)

Full Changelog: https://github.com/coursier/coursier/compare/v2.1.25...v2.1.26