**Problem**
Scripts with scalaVersion 3.x in /*** */ and a shebang fail: -Xscript is
ignored by Scala 3, and the shebang line causes "Expected a toplevel
definition".
**Solution**
- Strip shebang when copying the script so the compiler never sees it.
- For Scala 3 only: do not add -Xscript; generate Main.scala wrapping the
script body in object Main { def main(...) = { ... } }; use it as the
single source and set run/mainClass to Main.
- For Scala 2: keep existing behavior (shebang stripped, -Xscript + script
base name).
- Use Def.uncached and ScalaArtifacts.isScala3(scalaVersion.value) so
embedded scalaVersion from /*** */ is respected.
**Problem**
When sbtn (native thin client) can't find a running sbt server, it prompts
to start one. There was no way to opt out of server auto-start from the
client side, which is needed for CI environments and scripting (sbt/sbt#7079).
**Solution**
Reuse the existing sbt.server.autostart system property in NetworkClient
to control whether sbtn should attempt to start a server. When no server is
running and sbt.server.autostart=false, sbtn exits with an error instead
of prompting.
Support setting this property via:
- sbtn --no-server compile (sets sbt.server.autostart=false)
- sbtn --autostart=false compile (new flag following sbt conventions)
- sbtn -Dsbt.server.autostart=false compile (direct system property)
- sbt --autostart=false compile (bash runner and sbtw)
This follows sbt's naming conventions for properties/options: positive
property names with =false opt-out (like --color=false, --supershell=false).
Fixessbt/sbt#7079
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Avoid launching sbt just to render --version by reading sbt.version directly from project/build.properties in the shell script, batch script, and sbtw wrapper. Tighten launcher integration assertions to verify version output no longer depends on the sbtVersion command output.
**Problem**
Running sbt 2.x with JDK 8 produces a confusing "server was not
detected" error because the JDK version check only required JDK 8+
and only ran in the non-native-client path.
**Solution**
Move java_version detection before the native client decision and add
checkJava17ForSbt2 that requires JDK 17+ when sbt major version >= 2.
Fixes#8813
* [2.x] fix: Fail early when sbt 2.x is run with JDK < 17 (sbtw)
Move JDK version check before native client decision in sbtw and
require JDK 17+ when build.properties declares sbt 2.x.
* [2.x] fix: Fail early when sbt 2.x is run with JDK < 17 (sbt.bat)
Move checkjava before native client decision in sbt.bat and require
JDK 17+ when build.properties declares sbt 2.x.
* [2.x] test: Add minimumJdkVersion helper and unit tests for sbtw
Extract JDK version check logic into Runner.minimumJdkVersion for
testability. Add RunnerSpec with tests for sbt 1.x, 2.x, and 3.x
version detection.
* [2.x] test: Bump fake java to JDK 17 for integration tests
The fake java script used by launcher integration tests reported
JDK 8. Since sbt 2.x now requires JDK 17+, the citest2 (sbt 2.x)
integration tests would fail with the new JDK version check.
* Simulate JDK 9+ rt.jar handling in fake java script
Instead of silently ignoring --rt-ext-dir (which causes sbt.bat
to mkdir on an empty string), properly simulate JDK 9+ behavior
by creating a temp directory with java9-rt-ext- prefix and a
dummy rt.jar inside it.
bitloi
Dream
kenji yoshida