Spek execution in IntelliJ using the Plugin is currently broken, because the plugin executes using junit-platform-launcher 1.0.0.M3 instead of the now expected M4 (see https://github.com/JetBrains/spek/issues/195).
Adding junit-platform-launcher 1.0.0.M4 to the test classpath is the suggested workaround.
Spek execution in IntelliJ using the Plugin is currently broken, because the plugin executes using junit-platform-launcher 1.0.0.M3 instead of the now expected M4 (see https://github.com/JetBrains/spek/issues/195).
Adding junit-platform-launcher 1.0.0.M4 to the test classpath is the suggested workaround.