Repository: flutter
Issue: flutter web always show a empty page in debug mode
Labels: c: crash,tool,engine,dependency: dart,a: debugging,platform-web,P2,team-web,triaged-web

## Steps to Reproduce

1. ...when i run a flutter web application, it always show a empty page
2. ...if i use device 'chrome web' , it will show 'Syncing files to device Chrome...' all the time
3. ...if i use device 'Web Server web' it will show 'Waiting for connection from Dart debug extension at http://localhost:56659…', and i have install Dart debug extension and click this extension at the right top corner, but it does not work.

## Logs


<details> 
<summary>logs</summary> 

```bash
    "name" : "iPad Pro (10.5-inch)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/28B8C1DF-7C8B-48A2-B7A9-ED0431E31B26\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/28B8C1DF-7C8B-48A2-B7A9-ED0431E31B26",
                            "udid" : "28B8C1DF-7C8B-48A2-B7A9-ED0431E31B26",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad--6th-generation-",
                            "state" : "Shutdown",
                            "name" : "iPad (6th generation)"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.watchOS-4-3" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/D4C09668-17A1-416A-A0C0-E20E7B5063E7\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/D4C09668-17A1-416A-A0C0-E20E7B5063E7",
                            "udid" : "D4C09668-17A1-416A-A0C0-E20E7B5063E7",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-38mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch - 38mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/0C4B9652-A9D0-4A9E-AED9-BBF2C5809979\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/0C4B9652-A9D0-4A9E-AED9-BBF2C5809979",
                            "udid" : "0C4B9652-A9D0-4A9E-AED9-BBF2C5809979",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-42mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch - 42mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/DF4255E5-FECC-479C-ABE0-ED49ED7DC636\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/DF4255E5-FECC-479C-ABE0-ED49ED7DC636",
                            "udid" : "DF4255E5-FECC-479C-ABE0-ED49ED7DC636",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-38mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 2 - 38mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/18282AE0-BB7C-487F-9A79-A8D1DAAF4429\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/18282AE0-BB7C-487F-9A79-A8D1DAAF4429",
                            "udid" : "18282AE0-BB7C-487F-9A79-A8D1DAAF4429",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-42mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 2 - 42mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/5DD8F0F2-153C-47E3-915F-2515F43D9202\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/5DD8F0F2-153C-47E3-915F-2515F43D9202",
                            "udid" : "5DD8F0F2-153C-47E3-915F-2515F43D9202",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-38mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 3 - 38mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A75B128A-9FFD-4A09-87FB-E3A7AD668862\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A75B128A-9FFD-4A09-87FB-E3A7AD668862",
                            "udid" : "A75B128A-9FFD-4A09-87FB-E3A7AD668862",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-42mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 3 - 42mm"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.tvOS-12-0" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/345FC267-077E-421F-9DF1-04C773F6EBD8\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/345FC267-077E-421F-9DF1-04C773F6EBD8",
                            "udid" : "345FC267-077E-421F-9DF1-04C773F6EBD8",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/94647DD8-ED02-4815-A823-5CFFB7160A31\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/94647DD8-ED02-4815-A823-5CFFB7160A31",
                            "udid" : "94647DD8-ED02-4815-A823-5CFFB7160A31",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-4K",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/6C9EBF76-602F-46DB-BC89-C99523690BF9\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/6C9EBF76-602F-46DB-BC89-C99523690BF9",
                            "udid" : "6C9EBF76-602F-46DB-BC89-C99523690BF9",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K (at 1080p)"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.iOS-12-1" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/87AE01E2-4202-4329-A179-D69405968574\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/87AE01E2-4202-4329-A179-D69405968574",
                            "udid" : "87AE01E2-4202-4329-A179-D69405968574",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-5s",
                            "state" : "Shutdown",
                            "name" : "iPhone 5s"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/AB147D08-FF82-4242-A67D-71DC7704E00A\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/AB147D08-FF82-4242-A67D-71DC7704E00A",
                            "udid" : "AB147D08-FF82-4242-A67D-71DC7704E00A",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-6-Plus",
                            "state" : "Shutdown",
                            "name" : "iPhone 6 Plus"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/AE237E81-267A-45E7-B315-6153141E7AF5\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/AE237E81-267A-45E7-B315-6153141E7AF5",
                            "udid" : "AE237E81-267A-45E7-B315-6153141E7AF5",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-6",
                            "state" : "Shutdown",
                            "name" : "iPhone 6"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/C44A3574-9760-4F46-A6BD-AF2BD3E92EE6\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/C44A3574-9760-4F46-A6BD-AF2BD3E92EE6",
                            "udid" : "C44A3574-9760-4F46-A6BD-AF2BD3E92EE6",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-6s",
                            "state" : "Shutdown",
                            "name" : "iPhone 6s"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A89FE51D-70E9-46F1-B22E-36712AD31217\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A89FE51D-70E9-46F1-B22E-36712AD31217",
                            "udid" : "A89FE51D-70E9-46F1-B22E-36712AD31217",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-6s-Plus",
                            "state" : "Shutdown",
                            "name" : "iPhone 6s Plus"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/C532422E-AA7C-48A0-AA60-ED44206561D7\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/C532422E-AA7C-48A0-AA60-ED44206561D7",
                            "udid" : "C532422E-AA7C-48A0-AA60-ED44206561D7",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-SE",
                            "state" : "Shutdown",
                            "name" : "iPhone SE"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A1769A3F-4D71-4214-820D-B0C6CCC91BDE\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A1769A3F-4D71-4214-820D-B0C6CCC91BDE",
                            "udid" : "A1769A3F-4D71-4214-820D-B0C6CCC91BDE",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-7",
                            "state" : "Shutdown",
                            "name" : "iPhone 7"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/BDD0F374-A1D5-4030-9D49-06A72FFB9FAD\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/BDD0F374-A1D5-4030-9D49-06A72FFB9FAD",
                            "udid" : "BDD0F374-A1D5-4030-9D49-06A72FFB9FAD",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-7-Plus",
                            "state" : "Shutdown",
                            "name" : "iPhone 7 Plus"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/43B162FC-463C-4E76-B7AF-3D38E7923DB9\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/43B162FC-463C-4E76-B7AF-3D38E7923DB9",
                            "udid" : "43B162FC-463C-4E76-B7AF-3D38E7923DB9",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-8",
                            "state" : "Shutdown",
                            "name" : "iPhone 8"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/CD6B0AB0-DCC6-4F51-A331-7AAEC8D42F07\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/CD6B0AB0-DCC6-4F51-A331-7AAEC8D42F07",
                            "udid" : "CD6B0AB0-DCC6-4F51-A331-7AAEC8D42F07",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-8-Plus",
                            "state" : "Shutdown",
                            "name" : "iPhone 8 Plus"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/0339C56F-2707-4CA7-BF2C-0D4F64C16B4F\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/0339C56F-2707-4CA7-BF2C-0D4F64C16B4F",
                            "udid" : "0339C56F-2707-4CA7-BF2C-0D4F64C16B4F",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-X",
                            "state" : "Shutdown",
                            "name" : "iPhone X"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/98CCED78-F809-498D-B2D7-4C6B04333B92\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/98CCED78-F809-498D-B2D7-4C6B04333B92",
                            "udid" : "98CCED78-F809-498D-B2D7-4C6B04333B92",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-XS",
                            "state" : "Shutdown",
                            "name" : "iPhone XS"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/0E806541-87B8-41D8-BCE1-A17C819CC476\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/0E806541-87B8-41D8-BCE1-A17C819CC476",
                            "udid" : "0E806541-87B8-41D8-BCE1-A17C819CC476",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-XS-Max",
                            "state" : "Shutdown",
                            "name" : "iPhone XS Max"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/94BEE2B1-4FA6-4CDD-91CC-0497909CAE98\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/94BEE2B1-4FA6-4CDD-91CC-0497909CAE98",
                            "udid" : "94BEE2B1-4FA6-4CDD-91CC-0497909CAE98",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPhone-XR",
                            "state" : "Shutdown",
                            "name" : "iPhone XR"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/0F7839EB-CD6A-4F46-8BC2-E1BA959BA839\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/0F7839EB-CD6A-4F46-8BC2-E1BA959BA839",
                            "udid" : "0F7839EB-CD6A-4F46-8BC2-E1BA959BA839",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Air",
                            "state" : "Shutdown",
                            "name" : "iPad Air"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/1C70D882-4A8D-4A32-A6E4-19052F7F7E68\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/1C70D882-4A8D-4A32-A6E4-19052F7F7E68",
                            "udid" : "1C70D882-4A8D-4A32-A6E4-19052F7F7E68",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Air-2",
                            "state" : "Shutdown",
                            "name" : "iPad Air 2"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/11D1AFDA-36FC-4A99-86E0-2182B39DE3B0\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/11D1AFDA-36FC-4A99-86E0-2182B39DE3B0",
                            "udid" : "11D1AFDA-36FC-4A99-86E0-2182B39DE3B0",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro--9-7-inch-",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (9.7-inch)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/BA5192E7-D0E6-4DFE-BE82-AC88B8BEBD11\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/BA5192E7-D0E6-4DFE-BE82-AC88B8BEBD11",
                            "udid" : "BA5192E7-D0E6-4DFE-BE82-AC88B8BEBD11",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (12.9-inch)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/DAED1C70-1AC8-428D-8907-8D2603958419\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/DAED1C70-1AC8-428D-8907-8D2603958419",
                            "udid" : "DAED1C70-1AC8-428D-8907-8D2603958419",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad--5th-generation-",
                            "state" : "Shutdown",
                            "name" : "iPad (5th generation)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/53CE792A-396E-49A1-93CF-ED1D107069AB\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/53CE792A-396E-49A1-93CF-ED1D107069AB",
                            "udid" : "53CE792A-396E-49A1-93CF-ED1D107069AB",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro--12-9-inch---2nd-generation-",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (12.9-inch) (2nd generation)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/BC391C92-A706-413E-ABAB-4ED2248C83BB\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/BC391C92-A706-413E-ABAB-4ED2248C83BB",
                            "udid" : "BC391C92-A706-413E-ABAB-4ED2248C83BB",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro--10-5-inch-",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (10.5-inch)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A8B4E459-5387-459B-8BB5-51A60484724E\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A8B4E459-5387-459B-8BB5-51A60484724E",
                            "udid" : "A8B4E459-5387-459B-8BB5-51A60484724E",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad--6th-generation-",
                            "state" : "Shutdown",
                            "name" : "iPad (6th generation)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/D35CF53D-5BE7-4ECC-BF37-0877691B393D\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/D35CF53D-5BE7-4ECC-BF37-0877691B393D",
                            "udid" : "D35CF53D-5BE7-4ECC-BF37-0877691B393D",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro--11-inch-",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (11-inch)"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/FFBDE47D-88BA-4A3B-B661-24FF09E9B787\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/FFBDE47D-88BA-4A3B-B661-24FF09E9B787",
                            "udid" : "FFBDE47D-88BA-4A3B-B661-24FF09E9B787",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.iPad-Pro--12-9-inch---3rd-generation-",
                            "state" : "Shutdown",
                            "name" : "iPad Pro (12.9-inch) (3rd generation)"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.watchOS-6-2" : [
                          {
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/271C66D3-7DCF-466D-B960-B65A8551EC64\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/271C66D3-7DCF-466D-B960-B65A8551EC64",
                            "udid" : "271C66D3-7DCF-466D-B960-B65A8551EC64",
                            "isAvailable" : true,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-40mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 4 - 40mm"
                          },
                          {
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/08BF8EF0-4630-40EF-9760-28FB5250767C\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/08BF8EF0-4630-40EF-9760-28FB5250767C",
                            "udid" : "08BF8EF0-4630-40EF-9760-28FB5250767C",
                            "isAvailable" : true,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-44mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 4 - 44mm"
                          },
                          {
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/C664C573-4B65-4610-98B6-6EAE7CE57B35\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/C664C573-4B65-4610-98B6-6EAE7CE57B35",
                            "udid" : "C664C573-4B65-4610-98B6-6EAE7CE57B35",
                            "isAvailable" : true,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-5-40mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 5 - 40mm"
                          },
                          {
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/32B48876-B9F2-418E-9E0B-041CAE04964A\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/32B48876-B9F2-418E-9E0B-041CAE04964A",
                            "udid" : "32B48876-B9F2-418E-9E0B-041CAE04964A",
                            "isAvailable" : true,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-5-44mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 5 - 44mm"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.tvOS-12-1" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/9BEA80DE-4AA3-421F-9054-7FBC678FCE58\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/9BEA80DE-4AA3-421F-9054-7FBC678FCE58",
                            "udid" : "9BEA80DE-4AA3-421F-9054-7FBC678FCE58",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A047692D-BA5B-479D-9CDC-B2EA7BA32392\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A047692D-BA5B-479D-9CDC-B2EA7BA32392",
                            "udid" : "A047692D-BA5B-479D-9CDC-B2EA7BA32392",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-4K",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/CDFE88EE-7507-452E-9342-DDBCA8A26042\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/CDFE88EE-7507-452E-9342-DDBCA8A26042",
                            "udid" : "CDFE88EE-7507-452E-9342-DDBCA8A26042",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K (at 1080p)"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.watchOS-5-0" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/A60D8D56-64B2-4B96-B9E5-9C0951A2C15D\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/A60D8D56-64B2-4B96-B9E5-9C0951A2C15D",
                            "udid" : "A60D8D56-64B2-4B96-B9E5-9C0951A2C15D",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-38mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 2 - 38mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/C8861952-DF59-429C-A8D9-F45DEF4E3C30\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/C8861952-DF59-429C-A8D9-F45DEF4E3C30",
                            "udid" : "C8861952-DF59-429C-A8D9-F45DEF4E3C30",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-2-42mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 2 - 42mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/13B2833E-EFE1-45EE-9BBC-085656F8EA6A\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/13B2833E-EFE1-45EE-9BBC-085656F8EA6A",
                            "udid" : "13B2833E-EFE1-45EE-9BBC-085656F8EA6A",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-38mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 3 - 38mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/7384E21B-ED5A-42CA-A7F0-78FA3FE45A3F\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/7384E21B-ED5A-42CA-A7F0-78FA3FE45A3F",
                            "udid" : "7384E21B-ED5A-42CA-A7F0-78FA3FE45A3F",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-3-42mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 3 - 42mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/71E0548E-FFAB-40A5-8C53-CE0B9B6AB9B3\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/71E0548E-FFAB-40A5-8C53-CE0B9B6AB9B3",
                            "udid" : "71E0548E-FFAB-40A5-8C53-CE0B9B6AB9B3",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-40mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 4 - 40mm"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/2600210A-420A-44B6-89CE-BE1FB15C278C\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/2600210A-420A-44B6-89CE-BE1FB15C278C",
                            "udid" : "2600210A-420A-44B6-89CE-BE1FB15C278C",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-Watch-Series-4-44mm",
                            "state" : "Shutdown",
                            "name" : "Apple Watch Series 4 - 44mm"
                          }
                        ],
                        "com.apple.CoreSimulator.SimRuntime.tvOS-11-3" : [
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/176C7ADC-E2F8-4EFD-8D10-DE534B9D54EF\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/176C7ADC-E2F8-4EFD-8D10-DE534B9D54EF",
                            "udid" : "176C7ADC-E2F8-4EFD-8D10-DE534B9D54EF",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/38139A9C-2584-4A96-AA05-030488CF45F0\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/38139A9C-2584-4A96-AA05-030488CF45F0",
                            "udid" : "38139A9C-2584-4A96-AA05-030488CF45F0",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-4K",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K"
                          },
                          {
                            "availabilityError" : "runtime profile not found",
                            "dataPath" : "\/Users\/zhengkaijie\/Library\/Developer\/CoreSimulator\/Devices\/287CC53A-3975-4738-BFC8-E052CEBB2DE8\/data",
                            "logPath" : "\/Users\/zhengkaijie\/Library\/Logs\/CoreSimulator\/287CC53A-3975-4738-BFC8-E052CEBB2DE8",
                            "udid" : "287CC53A-3975-4738-BFC8-E052CEBB2DE8",
                            "isAvailable" : false,
                            "deviceTypeIdentifier" : "com.apple.CoreSimulator.SimDeviceType.Apple-TV-4K-1080p",
                            "state" : "Shutdown",
                            "name" : "Apple TV 4K (at 1080p)"
                          }
                        ]
                      }
                    }
[ +375 ms] Updating assets
[ +178 ms] Syncing files to device Chrome...
[  +83 ms] Generating /Users/zhengkaijie/Desktop/FlutterWeb/flutter_web/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
[  +56 ms] <- reset
[   +9 ms] /Users/zhengkaijie/development/flutter/bin/cache/dart-sdk/bin/dart --disable-dart-dev
/Users/zhengkaijie/development/flutter/bin/cache/artifacts/engine/darwin-x64/frontend_server.dart.snapshot --sdk-root /Users/zhengkaijie/development/flutter/bin/cache/flutter_web_sdk/
--incremental --target=dartdevc --debugger-module-names --experimental-emit-debug-metadata -Ddart.developer.causal_async_stacks=true --output-dill
/var/folders/ky/0zq60m8s00n4pybxw7j13grrbr3ywr/T/flutter_tools.7AVzfV/flutter_tool.snwTna/app.dill --libraries-spec
file:///Users/zhengkaijie/development/flutter/bin/cache/flutter_web_sdk/libraries.json --packages .packages -Ddart.vm.profile=false -Ddart.vm.product=false
--bytecode-options=source-positions,local-var-info,debugger-stops,instance-field-initializers,keep-unreachable-code,avoid-closure-call-instructions --enable-asserts
--track-widget-creation --filesystem-root /var/folders/ky/0zq60m8s00n4pybxw7j13grrbr3ywr/T/flutter_tools.7AVzfV/flutter_tools.rj5eAK --filesystem-scheme org-dartlang-app
--initialize-from-dill build/cache.dill.track.dill --platform file:///Users/zhengkaijie/development/flutter/bin/cache/flutter_web_sdk/kernel/flutter_ddc_sdk.dill
[  +34 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[+1755 ms] [
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone12,8",
                        "identifier" : "521053AC-2DE4-4D79-8E0D-4100ECC1A08A",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-se-1",
                        "modelName" : "iPhone SE (2nd generation)",
                        "name" : "iPhone SE (2nd generation)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone10,5",
                        "identifier" : "BA164B2C-6BA4-44B9-B87A-882D84EE72A9",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-8-plus-2",
                        "modelName" : "iPhone 8 Plus",
                        "name" : "iPhone 8 Plus"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "6.2.1 (17T531)",
                        "available" : true,
                        "platform" : "com.apple.platform.watchsimulator",
                        "modelCode" : "Watch4,3",
                        "identifier" : "271C66D3-7DCF-466D-B960-B65A8551EC64",
                        "architecture" : "i386",
                        "modelUTI" : "com.apple.watch-series4-1",
                        "modelName" : "Apple Watch Series 4 - 40mm",
                        "name" : "Apple Watch Series 4 - 40mm"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone12,3",
                        "identifier" : "C339401D-E053-407D-9080-9ECEA06FEAA3",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-11-pro-1",
                        "modelName" : "iPhone 11 Pro",
                        "name" : "iPhone 11 Pro"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "6.2.1 (17T531)",
                        "available" : true,
                        "platform" : "com.apple.platform.watchsimulator",
                        "modelCode" : "Watch4,4",
                        "identifier" : "08BF8EF0-4630-40EF-9760-28FB5250767C",
                        "architecture" : "i386",
                        "modelUTI" : "com.apple.watch-series4-1",
                        "modelName" : "Apple Watch Series 4 - 44mm",
                        "name" : "Apple Watch Series 4 - 44mm"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPad8,1",
                        "identifier" : "6448891F-1F77-41CA-B72F-19F698961DCF",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.ipad-pro-11-1",
                        "modelName" : "iPad Pro (11-inch) (1st generation)",
                        "name" : "iPad Pro (11-inch)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.4 (17L255)",
                        "available" : true,
                        "platform" : "com.apple.platform.appletvsimulator",
                        "modelCode" : "AppleTV6,2",
                        "identifier" : "12EE1B84-6A9C-44B4-A603-000B8FD4EF13",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.apple-tv-4k",
                        "modelName" : "Apple TV 4K (at 1080p)",
                        "name" : "Apple TV 4K (at 1080p)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPad6,4",
                        "identifier" : "0786E6B6-041D-4DC1-B4AA-EEF5FEC271C4",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.ipad-pro-9point7-a1674-b9b7ba",
                        "modelName" : "iPad Pro (9.7-inch)",
                        "name" : "iPad Pro (9.7-inch)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "6.2.1 (17T531)",
                        "available" : true,
                        "platform" : "com.apple.platform.watchsimulator",
                        "modelCode" : "Watch5,3",
                        "identifier" : "C664C573-4B65-4610-98B6-6EAE7CE57B35",
                        "architecture" : "i386",
                        "modelUTI" : "com.apple.watch-series5-1",
                        "modelName" : "Apple Watch Series 5 - 40mm",
                        "name" : "Apple Watch Series 5 - 40mm"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPad8,5",
                        "identifier" : "90645CF0-47F5-42F7-B003-D3D6F726DCD4",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.ipad-pro-12point9-1",
                        "modelName" : "iPad Pro (12.9-inch) (3rd generation)",
                        "name" : "iPad Pro (12.9-inch) (3rd generation)"
                      },
                      {
                        "simulator" : false,
                        "operatingSystemVersion" : "12.4.5 (16G161)",
                        "interface" : "usb",
                        "available" : true,
                        "platform" : "com.apple.platform.iphoneos",
                        "modelCode" : "iPhone7,1",
                        "identifier" : "a9ceaf41bb967abb747a0249768d9abd45d5a07b",
                        "architecture" : "arm64",
                        "modelUTI" : "com.apple.iphone-6-plus-e1ccb5",
                        "modelName" : "iPhone 6 Plus",
                        "name" : "iPhone (3)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPad8,12",
                        "identifier" : "432CED11-2D42-4931-B3D4-20D078396E6E",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.ipad-pro-12point9-4th-1",
                        "modelName" : "iPad Pro (12.9-inch) (4th generation)",
                        "name" : "iPad Pro (12.9-inch) (4th generation)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.4 (17L255)",
                        "available" : true,
                        "platform" : "com.apple.platform.appletvsimulator",
                        "modelCode" : "AppleTV5,3",
                        "identifier" : "BC54F91C-DE0B-4B48-ADE8-1EFBDA4A1E99",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.apple-tv-4",
                        "modelName" : "Apple TV",
                        "name" : "Apple TV"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone12,1",
                        "identifier" : "BE898F74-C88A-4E19-AD25-DFE46A2DC0BC",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-11-1",
                        "modelName" : "iPhone 11",
                        "name" : "iPhone 11"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.4 (17L255)",
                        "available" : true,
                        "platform" : "com.apple.platform.appletvsimulator",
                        "modelCode" : "AppleTV6,2",
                        "identifier" : "60DCB02D-9FCA-44FA-92A4-29C6B2DBDE10",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.apple-tv-4k",
                        "modelName" : "Apple TV 4K",
                        "name" : "Apple TV 4K"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone12,5",
                        "identifier" : "B3D4D5AB-240D-43CB-8A7C-4E55DE5DE9D3",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-11-pro-max-1",
                        "modelName" : "iPhone 11 Pro Max",
                        "name" : "iPhone 11 Pro Max"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPad8,9",
                        "identifier" : "4DFC3F5F-7FCC-4CAB-BEA1-C340B9E315D7",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.ipad-pro-11-2nd-1",
                        "modelName" : "iPad Pro (11-inch) (2nd generation)",
                        "name" : "iPad Pro (11-inch) (2nd generation)"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
                        "platform" : "com.apple.platform.iphonesimulator",
                        "modelCode" : "iPhone10,4",
                        "identifier" : "4259BF1F-E85C-4596-A738-E3B5C65ABF36",
                        "architecture" : "x86_64",
                        "modelUTI" : "com.apple.iphone-8-2",
                        "modelName" : "iPhone 8",
                        "name" : "iPhone 8"
                      },
                      {
                        "simulator" : true,
                        "operatingSystemVersion" : "13.7 (17H22)",
                        "available" : true,
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[  +20 ms] [
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               "platform" : "com.apple.platform.iphonesimulator",
               "modelCode" : "iPhone12,5",
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               "architecture" : "x86_64",
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               "architecture" : "x86_64",
               "modelUTI" : "com.apple.ipad-pro-11-2nd-1",
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               "identifier" : "4259BF1F-E85C-4596-A738-E3B5C65ABF36",
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               "identifier" : "F2361425-7F2C-4017-AA30-9532FD06C9AC",
               "architecture" : "x86_64",
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               "modelName" : "iPad Air (3rd generation)",
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               "operatingSystemVersion" : "13.7 (17H22)",
               "available" : true,
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               "identifier" : "E4F923BF-A924-4692-BEB4-45D4F04D8903",
               "architecture" : "x86_64",
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               "modelName" : "iPad (7th generation)",
               "name" : "iPad (7th generation)"
             },
             {
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               "operatingSystemVersion" : "6.2.1 (17T531)",
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               "platform" : "com.apple.platform.watchsimulator",
               "modelCode" : "Watch5,4",
               "identifier" : "32B48876-B9F2-418E-9E0B-041CAE04964A",
               "architecture" : "i386",
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           ]
[+17396 ms] Syncing files to device Chrome... (completed in 19,346ms, longer than expected)
[        ] Synced 26.9MB.
[        ] <- accept
[        ] Caching compiled dill
[+2346 ms] [CHROME]:
[        ] [CHROME]:DevTools listening on ws://127.0.0.1:55725/devtools/browser/bd6dba84-0430-4ff8-a96e-180936ceecae


```

</details> 

<details> 
<summary>flutter doctor -v</summary> 

```bash
[✓] Flutter (Channel beta, 1.22.0-12.1.pre, on Mac OS X 10.15.3 19D76, locale zh-Hans-CN)
    • Flutter version 1.22.0-12.1.pre at /Users/zhengkaijie/development/flutter
    • Framework revision 8b3760638a (6 days ago), 2020-09-15 17:47:13 -0700
    • Engine revision 4654fc6cf6
    • Dart version 2.10.0 (build 2.10.0-110.3.beta)

 
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at /Users/zhengkaijie/Library/Android/sdk
    • Platform android-30, build-tools 30.0.1
    • ANDROID_HOME = /Users/zhengkaijie/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.7)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.7, Build version 11E801a
    • CocoaPods version 1.9.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 48.1.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.49.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.14.1

[✓] Connected device (3 available)
    • iPhone (3) (mobile) • a9ceaf41bb967abb747a0249768d9abd45d5a07b • ios            • iOS 12.4.5
    • Web Server (web)    • web-server                               • web-javascript • Flutter Tools
    • Chrome (web)        • chrome                                   • web-javascript • Google Chrome 85.0.4183.102 

```
</details>