我从https://github.com/Backelite/sonar-objective-c 下载了源码，用 maven（mvn package）编译打包 backelite-sonar-objective-c-plugin-0.6.3.jar，放到 extensions/plugin 目录下，但是启动的时候 sonarqube 报错，加载 oc 插件不成功，我的 sonarqube 版本是 7.4，机器硬件是 “Darwin secneodeMac-mini-5.local 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64 x86_64” ，请问这是因为什么原因？

2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin Git / 1.6.0.1349 / 5324aafc7d16337ca792fec35903d0d313c9e2c7
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin JaCoCo / 1.0.1.143 / 65c55e41e32c114704fd597ccea91fc55becb4ec
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin LDAP / 2.2.0.608 / 79dc3fa4393a29667673c70182f3016288b548b7
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin ObjectiveC (Backelite) / 0.6.3
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarC# / 7.7.0.7192 / c46d44cdae6e75538626f380fe3fa7553e6cf93d
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarCSS / 1.0.2.611 / 8db5e31b2e21ff683da69668ec577c7a026acf23
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarFlex / 2.4.0.1222 / 68d9cb3b7daccbc4869c4f2b89d09218d26a0829
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarGo / 1.1.0.1612 / 1809c7be6d88396c0a1b8d597b1e9e0ed8d29730
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarJS / 5.0.0.6962 / ac2fe7567f3dfeb3295e2e710afd8c06b7760e9d
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarJava / 5.8.0.15699 / 34186ed1499e6166d3ef8670086d05ab6f12f6f9
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarKotlin / 1.2.1.2009 / 3dd3ade901a10bc88a7158c014eba9f5a568951c
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarPHP / 2.14.0.3569 / 59a202b8d1c5276ce32da2a0bc63c94cae4cdeb2
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarPython / 1.10.0.2131 / a00e0ddc83bbeb01a9ee7475fab9eafe3f4096ac
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarRuby / 1.2.1.2009 / 3dd3ade901a10bc88a7158c014eba9f5a568951c
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarTS / 1.8.0.3332 / af8e41ab1a72ba3cc28b0e3e9e065a0ccb47d31d
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarVB / 7.7.0.7192 / c46d44cdae6e75538626f380fe3fa7553e6cf93d
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin SonarXML / 1.5.1.1452 / eadc1dcd0e24a3c77068e3c1d41af0327d6b16ea
2019.08.15 10:49:38 INFO web[][o.s.s.p.ServerPluginRepository] Deploy plugin Svn / 1.9.0.1295 / 942e075773975354e32691a60bfd968065703e04
2019.08.15 10:49:39 INFO web[][o.s.s.p.w.MasterServletFilter] Initializing servlet filter org.sonar.server.ws.WebServiceFilter@19fa25c2 [pattern=UrlPattern{inclusions=[/api/system/migrate_db., ...], exclusions=[/api/properties, ...]}]
2019.08.15 10:49:39 INFO web[][o.s.s.a.EmbeddedTomcat] HTTP connector enabled on port 9000
2019.08.15 10:49:40 WARN web[][o.s.c.p.ComponentKeys] Bad component key: org.sonar.java.externalreport.ExternalRulesDefinition@13a84755. Please implement toString() method on class org.sonar.java.externalreport.ExternalRulesDefinition
2019.08.15 10:49:40 WARN web[][o.s.c.p.ComponentKeys] Bad component key: org.sonar.java.externalreport.ExternalRulesDefinition@2054717d. Please implement toString() method on class org.sonar.java.externalreport.ExternalRulesDefinition
2019.08.15 10:49:40 WARN web[][o.s.c.p.ComponentKeys] Bad component key: org.sonar.java.externalreport.ExternalRulesDefinition@6103baea. Please implement toString() method on class org.sonar.java.externalreport.ExternalRulesDefinition
2019.08.15 10:49:40 ERROR web[][o.s.s.p.Platform] Background initialization failed. Stopping SonarQube
java.lang.IllegalStateException: Fail to load plugin ObjectiveC (Backelite) [backelitesonarobjectivecplugin]
at org.sonar.server.plugins.ServerExtensionInstaller.installExtensions(ServerExtensionInstaller.java:82)
at org.sonar.server.platform.platformlevel.PlatformLevel4.start(PlatformLevel4.java:586)
at org.sonar.server.platform.Platform.start(Platform.java:211)
at org.sonar.server.platform.Platform.startLevel34Containers(Platform.java:185)
at org.sonar.server.platform.Platform.access$500(Platform.java:46)
at org.sonar.server.platform.Platform$1.lambda$doRun$0(Platform.java:119)
at org.sonar.server.platform.Platform$AutoStarterRunnable.runIfNotAborted(Platform.java:371)
at org.sonar.server.platform.Platform$1.doRun(Platform.java:119)
at org.sonar.server.platform.Platform$AutoStarterRunnable.run(Platform.java:355)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NoClassDefFoundError: org/sonar/api/batch/AbstractCpdMapping
at java.lang.ClassLoader.defineClass1(Native Method)