objc[9318]: Class AppleTypeCRetimerRestoreInfoHelper is implemented in both /usr/lib/libauthinstall.dylib (0x207c11eb0) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d984f8). One of the two will be used. Which one is undefined.
objc[9318]: Class AppleTypeCRetimerFirmwareAggregateRequestCreator is implemented in both /usr/lib/libauthinstall.dylib (0x207c11f00) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d98548). One of the two will be used. Which one is undefined.
objc[9318]: Class AppleTypeCRetimerFirmwareRequestCreator is implemented in both /usr/lib/libauthinstall.dylib (0x207c11f50) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d98598). One of the two will be used. Which one is undefined.
objc[9318]: Class ATCRTRestoreInfoFTABFile is implemented in both /usr/lib/libauthinstall.dylib (0x207c11fa0) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d985e8). One of the two will be used. Which one is undefined.
objc[9318]: Class AppleTypeCRetimerFirmwareCopier is implemented in both /usr/lib/libauthinstall.dylib (0x207c11ff0) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d98638). One of the two will be used. Which one is undefined.
objc[9318]: Class ATCRTRestoreInfoFTABSubfile is implemented in both /usr/lib/libauthinstall.dylib (0x207c12040) and /Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice (0x103d98688). One of the two will be used. Which one is undefined.

Potete provare con:

sudo xcode-select -r
sudo xcode-select -s /Library/Developer/CommandLineTools

Qualora non dovesse ancora funzionare, provate a reinstallare cocoapods tramite homebrew:

brew install cocoapods

enjoy!