fix(build): target Java 21 bytecode so 1.21 servers can load the plugin - #176
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#175 raised both the toolchain and the release to 25, which emits class file 69 and makes the plugin unloadable on any JVM below 25. Minecraft 1.21 requires Java 21, so stock servers at the low end of the supported range would fail with UnsupportedClassVersionError despite the API compatibility work in that PR. Nothing in the dependency chain justified the higher target: the Spigot API is class file 61 in both 1.21 and 26.2, and the highest bundled library is also 61. The sources use no language feature past 21 either. Keep building on JDK 25 and lower the emitted bytecode to 21 by splitting the single JAVA constant into JAVA_TOOLCHAIN and JAVA_RELEASE. The shipped jar now tops out at class file 65 and loads on Java 21 and newer. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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#175 raised both the toolchain and the release to 25, which emits class file 69 and makes the plugin unloadable on any JVM below 25. Minecraft 1.21 requires Java 21, so stock servers at the low end of the supported range would fail with UnsupportedClassVersionError despite the API compatibility work in that PR.
Nothing in the dependency chain justified the higher target: the Spigot API is class file 61 in both 1.21 and 26.2, and the highest bundled library is also 61. The sources use no language feature past 21 either.
Keep building on JDK 25 and lower the emitted bytecode to 21 by splitting the single JAVA constant into JAVA_TOOLCHAIN and JAVA_RELEASE. The shipped jar now tops out at class file 65 and loads on Java 21 and newer.
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