On 20 May 2021, at 15:16, Roberto Avanzi via TextMate wrote:

cp: /Users/mocenigo/build/textmate/release/_CompileXib/Frameworks/BundleEditor/resources/English.lproj/GrammarProperties.nib
is a directory (not copied).

How can I set up the environment to just build properly, with "ninja
TextMate" and not stopping on the cp commands?

This is puzzling because in the above, GrammarProperties.nib should not be a directory.

It is created from the GrammarProprties.xib using xcrun ibtool --compile.

You can try to experiment with ibtool yourself, for example, the man page for this tool says the following:

--flatten boolean
    When combined with the --compile option and a value of NO, --flatten instructs
    ibtool to produce an output file that is both runnable, and editable. This
    option is typically used when preparing a product for localization. If no value
    is specified, the default flattening option is YES.

It might be that --flatten defaults to NO in your build environment, and that causes a directory to be created?

Btw: If you are only doing your own builds to get ARM support then current release builds are universal.