Since I updated my Mac mini M1 to Big Sur 11.2.1 a few hours ago, I cannot compile universal apps anymore. I get the following error message:
Error signing application: xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
[My volume] - Gramma/macOS Universal/Gramma.app: the codesign_allocate helper tool cannot be found or used
In subcomponent: [My volume]/Xojo/Builds - Gramma/macOS Universal/Gramma.app/Contents/Frameworks/HTMLViewerCocoa.dylib
Open Terminal, and run the following:
xcode-select --install
This will download and install the Command Line Tools package and fix the problem.
You do not need Xcode, you can install only the Command Line Tools here, it is about 130Mb.
If the above alone doesn't do it, then also run:
xcode-select --reset