I've my own open-source CLI tool called surmagic. In my latest update, I've built on a different machine, which has an M1 CPU. Before and after publishing I've tested on that machine, via installing the homebrew. And it works as expected. After a while, I've tested on another machine that has an Intel CPU. And, I've been faced with this error:

> surmagic --version
zsh: bad CPU type in executable: surmagic

I know what this error means from other libraries that I've used before, but the problem is how to solve this error as a CLI tool provider is another question.

I need help with this. How to solve this forever.

Solution

First, check your Mac's architecture via the command below:

> arch
i386

if your result is i386 like in my case. Then check the application binary's architecture via the command below:

> cd /usr/local/bin
> lipo -info surmagic
Non-fat file: surmagic is architecture: arm64

if this result is arm64 non-fat, like in my case, then you need to build a FAT executable for your library.

Follow the steps below:

How to Build a Universal Binary

Firstly, make sure that you are using the correct version of Xcode/Swift:

> xcrun swift build --version
Swift Package Manager - Swift 5.5.0

Note: If this is not Swift 5.3 or greater, use xcode-select -s to switch to the Xcode 12 beta.

Now, when compiling your package, specify both architectures to compile a Universal Binary (the real irony here is my CLI tool actually makes FAT libraries for Xcode project):

> xcrun swift build -c release --arch arm64 --arch x86_64

To verify that your built binary contains both architectures, you can use the lipo -info command to inspect a binary and confirm:

> lipo -info .build/apple/Products/Release/surmagic
Architectures in the fat file: .build/apple/Products/Release/surmagic are: x86_64 arm64

If successful, you should see both x86_64 and arm64.