metal binary linked functions causing segmentation fault

I'm trying to follow WWDC2020/21 in making simplest use of Metal's binary linked functions.

I attach a visible function with CompileToBinary to the binary linked functions of a compute pipeline descriptor. I'm getting a segmentation fault (I think), which occurs as the program suspending with Thread 1: EXC_BAD_ACCESS (code=1, address=0x10) where the device creates the pipeline (the program not reaching the NSLog). I can't figure out how to address this with memory debugging tools. Some points:

1. Checking all relevant objects right before making the call ([device newComputePipeline...]) yields expected results.
2. I get the same error when making the call asynchronously.
3. Adding visible_func to linked functions instead of binaryFunctions works.
4. I've also been following the FunctionPointersAndStitching example code (for rendering rather than compute) to make sure I'm setting needed properties and creating things in the right order.
5. I can't even begin to use these linked functions (creating a visible function table), until I create the pipeline, so stopping short after creating the pipeline doesn't seem a candidate issue.

#import <Foundation/Foundation.h>
#import <Metal/Metal.h>
 
int main() {
    @autoreleasepool {
        id<MTLDevice> device = MTLCreateSystemDefaultDevice();
        id<MTLLibrary> lib = [device newDefaultLibrary];
        id<MTLFunction> kernel_func = [lib newFunctionWithName:@"kernel_func"];
        
        MTLFunctionDescriptor * visible_func_desc = [MTLFunctionDescriptor functionDescriptor];
        visible_func_desc.name = @"visible_func";
        visible_func_desc.options = MTLFunctionOptionCompileToBinary;
        NSError * error = nil;
        id<MTLFunction> visible_func = [lib newFunctionWithDescriptor:visible_func_desc error: &error];
        
        MTLLinkedFunctions *linked_funcs = [MTLLinkedFunctions linkedFunctions];
        linked_funcs.binaryFunctions = @[visible_func];
        
        MTLComputePipelineDescriptor * pipeline_desc = [MTLComputePipelineDescriptor new];
        pipeline_desc.linkedFunctions = linked_funcs;
        pipeline_desc.computeFunction = kernel_func;
        
        MTLAutoreleasedComputePipelineReflection * reflection = nil;
        id<MTLComputePipelineState> pipeline = [device newComputePipelineStateWithDescriptor:pipeline_desc options:MTLPipelineOptionNone reflection:reflection error:&error];
        
        if(pipeline == nil) {
            NSLog(@"Error making pipeline: %@",error);
        }
    }
}

#include <metal_stdlib>
using namespace metal;
 
[[visible]] int visible_func(int x, int y) {
    return x + y;
}
 
[[kernel]] void kernel_func(uint gid [[ thread_position_in_grid ]])
{
    gid;
}