Compiler xib exécuter ibtool xxx.xib - - compile xxx.nib erreur de Times:

Compiler xib exécuter ibtool xxx.xib - - compile xxx.nib erreur de Times:
xcode-select: error: tool ‘ibtool’ requires Xcode, but active developer directory ‘/Library/Developer/CommandLineTools’ is a command line tools instance

‘ibtool’ is a program that is installed as part of Xcode.

You only need to convert the .xib if you have edited it in Xcode. So ether ignore the .xib or install Xcode and edit the file.

I have installed xcode and edited the xib file using code. Then, I opened the terminal and executed the above command, but an error was reported.

How to install ibtool after I have installed xcode

Start Xcode. It should ask to install command line tools.
You might be able to trigger it by running this: xcode-select --install in the Terminal.