Cannot build for iOS : flutter run failed

[milochen0418]

$ git clone https://github.com/cloudwebrtc/flutter-webrtc-demo
$ cd flutter-webrtc-demo
$ open -a Simulator
$ flutter packages get
$ flutter run

Then I got this error message.

[!] Invalid `Podfile` file: no implicit conversion of nil into String.

 #  from /Users/pebblarmbp/git/flutter-webrtc-demo/ios/Podfile:54
 #  -------------------------------------------
 #      unless File.exist?(copied_framework_path)
 >        FileUtils.cp_r(File.join(cached_framework_dir, 'Flutter.framework'), copied_flutter_dir)
 #      end
 #  -------------------------------------------

It's look like pod install cannot work.

My PC environment is
XCode Version 12.5 (12E262)
macOS Big Sur (Version 11.3.1)

Flutter environment
$ flutter --version
Flutter 2.0.6 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 1d9032c7e1 (10 days ago) • 2021-04-29 17:37:58 -0700
Engine • revision 05e680e202
Tools • Dart 2.12.3

By the way, This is the Screenshot on my Mac

[milochen0418]

I use lastest XCode, macOS, flutter and pod. install 2021/05/10
The version information is here.

macOS Big Sur
Version 11.3.1

Pod version
1.10.1

XCode
Version 12.5 (12E262)

Flutter 2.0.6 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 1d9032c7e1 (11 days ago) • 2021-04-29 17:37:58 -0700
Engine • revision 05e680e202
Tools • Dart 2.12.3

[milochen0418]

The way to solve this issue is to re-generate new Podfile.
$ rm ios/Podfile
$ flutter create .

[milochen0418]

Issue have been solved by re-generate new Podfile.
c042316

So close this issue.