Javascript IOs生成失败，退出代码为65

我有一个离子3应用程序。我正在尝试使用创建ios生成，但失败，出现以下错误：

The following build commands failed:
        CompileC /Users/jasontxf/Library/Developer/Xcode/DerivedData/ManyTutors-gciyzubmaljrbkejonynzshevvin/Build/Intermediates.noindex/ArchiveIntermediates/ManyTutors/IntermediateBuildFilesPath/ManyTutors.build/Release-iphoneos/ManyTutors.build/Objects-normal/arm64/CDVWKWebViewEngine.o /Users/jasontxf/Dropbox/ask-manytutors-v6/platforms/ios/ManyTutors/Plugins/cordova-plugin-ionic-webview/CDVWKWebViewEngine.m normal arm64 objective-c com.apple.compilers.llvm.clang.1_0.compiler
(1 failure) 
(node:65230) UnhandledPromiseRejectionWarning: Error: xcodebuild: Command failed with exit code 65
    at ChildProcess.whenDone (/Users/jasontxf/Dropbox/ask-manytutors-v6/node_modules/cordova-common/src/superspawn.js:136:25)
    at ChildProcess.emit (events.js:189:13)
    at maybeClose (internal/child_process.js:970:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
(node:65230) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:65230) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

我已尝试使用以下命令创建生成：

ionic cordova build ios --buildFlag="-UseModernBuildSystem=0" --release
ionic cordova build ios --release

第一个我用来强迫它使用最新的构建系统。我还从Xcode的文件=>项目设置=>最新版本系统（默认）更改为最新版本

项目配置

Ionic Version: 3.9.2
cordova-ios: 6+
node version: 10.15.1
Xcode Version: 12+

如有任何建议，将不胜感激