Error: 'kethrow' isn't a type. kethrow _ClientSocketException(error, request.url); - flutter

Question

Building flutter application is giving an error.When i try to build my application the error is occured.
The error is:
**/C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_client.dart:88:7: Error: 'kethrow' isn't a type.
kethrow _ClientSocketException(error, request.url);
^^^^^^^
/C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_client.dart:88:15: Error: Expected ';' after this.
kethrow _ClientSocketException(error, request.url);
^^^^^^^^^^^^^^^^^^^^^^
/C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_client.dart:88:43: Error: Expected ')' before this.
kethrow _ClientSocketException(error, request.url);
^
/C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_client.dart:48:30: Error: A non-null value must be returned since the return type 'IOStreamedResponse' doesn't allow null.
- 'IOStreamedResponse' is from 'package:http/src/io_streamed_response.dart' ('/C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_streamed_response.dart').
package:http/src/io_streamed_response.dart:1
Future<IOStreamedResponse> send(BaseRequest request) async {
^
3
FAILURE: Build failed with an exception.
* Where:
Script 'C:\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 1156
* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command 'C:\flutter\bin\flutter.bat'' finished with non-zero exit value 1
* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 5m 45s
Exception: Gradle task assembleDebug failed with exit code 1**
How to fix this error.Thanks in advance.

Answer 1

I ran into this error a few days ago. It is strangely from the dart file. Mine was 'heethrow'. I corrected it by following the link to the file: /C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/io_client.dart.
How to go about it:
Open location /C:/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.13.5/lib/src/ in Visual Studio Code
inside the src folder, open io_client.dart
(make sure you're in the io_client.dart inside the src folder)
Once you're in io_client.dart, locate the place with the error: in your case, it says 88:7 that is, line 88 column 7. Scroll to line number 88 and change 'kethrow' to 'throw'
the errors in the other places as marked in the image below should be corrected and your io_client.dart should be error free.
Note: other files outside io_client.dart might mark red indicating errors but never mind. Just save your changes in the io_client.dart file and close the file. Once closed
Open your project again and run flutter clean in the terminal.
next run flutter pub get
next run flutter pub upgrade
run your app again, everything should work fine.
But I'd advise you don't always go into those files to edit anything. I did that because I've tried every possible solution and needed to deliver my work. I even installed Visual Studio for Windows as suggested by flutter doctor, but that was not the solution.