MatrixSDK Pod error : [!] Error installing MatrixSDK [!] Failed to download 'MatrixSDK':

Hi,

i cloned riot-ios project from branch -> xcode11 , when i'm pod installing this kind of error occured. please how to fix this issue...

im using -->. xcode 11.3. ---> iOS 13. ,and macOS--> Catalina-10.15.2
please help me any sugestion....
[
i tried and followed this link but still not fixed issue...](https://github.com/vector-im/riot-ios/issues/3181)

[!] Error installing MatrixSDK
[!] Failed to download 'MatrixSDK': [!] /usr/bin/git -C /var/folders/2n/r0cgbb_d2677pwrfwjhch0jw0000gn/T/d20200506-1676-cryoqd checkout --quiet f011e86db576d6c7e1425a72c19f93264e655ae4

fatal: reference is not a tree: f011e86db576d6c7e1425a72c19f93264e655ae4