**Problem**
sbt bspConfig writes the absolute path of the current Java binary into .bsp/sbt.json. When the user switches Java versions (via sdkman, cs java, etc.) or removes that JDK, the IDE fails to start the sbt BSP server because the hardcoded path is stale or gone.
**Solution**
When an sbt launcher script is available (via `sbt.script` system property or PATH lookup), generate:
"argv": ["/path/to/sbt", "bsp"]
**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.
Co-authored-by: Dream <42954461+eureka928@users.noreply.github.com>
BitToby
eugene yokota
kenji yoshida
bitloi