命令行构建ios，加了sourceMaps=true，构建报错
[48356] Error: Build Failed: Error: Error: Cannot read property '0' of null
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/page/build/compile-worker.ccc:1:6469
at Gulp.<anonymous> (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/page/build/compile-worker.ccc:1:6498)
at Object.onceWrapper (events.js:422:26)
at Gulp.emit (events.js:315:20)
at Gulp.emit (domain.js:467:12)
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/page/build/compile-worker.ccc:1:992
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/core/gulp-build.ccc:1:28496
at Gulp.<anonymous> (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/core/gulp-build.ccc:1:28552)
at Object.onceWrapper (events.js:422:26)
at Gulp.emit (events.js:315:20)
at Gulp.emit (domain.js:467:12)
at Object.error (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/undertaker/lib/helpers/createExtensions.js:61:10)
at handler (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/now-and-later/lib/mapSeries.js:47:14)
at f (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/once/once.js:25:25)
at f (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/once/once.js:25:25)
at tryCatch (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/async-done/index.js:24:15)
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/lib/builder/index.ccc:1:4014
at wrapper (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/async/dist/async.js:272:20)
at next (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/async/dist/async.js:4584:24)
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/node_modules/async/dist/async.js:325:20
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/core/gulp-build.ccc:1:27288
at /Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/core/gulp-build.ccc:1:5999
at Gulp.<anonymous> (/Applications/CocosCreator/Creator/2.4.7/CocosCreator.app/Contents/Resources/app.asar/editor/core/gulp-build.ccc:1:28390)
at Object.onceWrapper (events.js:422:26)
at Gulp.emit (events.js:315:20)