28.7 Building universal binaries

You can build a universal binary on an Apple silicon Macintosh computer by choosing Build > Build Universal or clicking the button, using the same script as was used to build a normal ("thin") image.

This actually runs two LispWorks subprocesses. One builds the Apple silicon (arm64) part of the binary, and the other builds the Intel (x86_64) part of the binary under Rosetta. Both LispWorks subprocesses load the script. Afterwards, the Application Builder creates the universal binary.

The Application Builder uses the script in the same way as save-universal-from-script. In particular, the functions building-main-architecture-p and building-universal-intermediate-p have the same behaviour.

When you have saved a universal binary, you can invoke it as Intel (x86_64) by choosing Build > Run With Arguments or clicking the toolbar button (see Running the saved application for details).

The option of building a universal binary is available only in an image that is itself a universal binary, such as the supplied LispWorks image, and runs on Apple silicon macOS.