[nix-shell:~/Downloads/zig/build]$ ./zig build-exe test3.zig 
Code Generation [43/560] std.debug.struct:1174:48.callback...Assertion failed at /home/andy/Downloads/zig/src/codegen.cpp:5527 in ir_render_breakpoint. This is a bug in the Zig compiler.
/home/andy/Downloads/zig/src-self-hosted/stage2.zig:36:5: 0xff004c in stage2_panic (zigstage2)
    @panic(ptr[0..len]);
    ^
/home/andy/Downloads/zig/src/util.cpp:20:17: 0xfb290c in zig_panic (/home/andy/Downloads/zig/src/util.cpp)
    stage2_panic("", 0);
                ^
/home/andy/Downloads/zig/src/util_base.hpp:53:18: 0xed9679 in zig_assert (/home/andy/Downloads/zig/src/codegen.cpp)
        zig_panic("Assertion failed at %s:%d in %s. This is a bug in the Zig compiler.", file, line, func);
                 ^
/home/andy/Downloads/zig/src/codegen.cpp:5527:5: 0xeef679 in ir_render_breakpoint (/home/andy/Downloads/zig/src/codegen.cpp)
    assert(false);
    ^
/home/andy/Downloads/zig/src/codegen.cpp:6369:40: 0xef298b in ir_render_instruction (/home/andy/Downloads/zig/src/codegen.cpp)
            return ir_render_breakpoint(g, executable, (IrInstGenBreakpoint *)instruction);
                                       ^
/home/andy/Downloads/zig/src/codegen.cpp:6487:60: 0xef305e in ir_render (/home/andy/Downloads/zig/src/codegen.cpp)
            instruction->llvm_value = ir_render_instruction(g, executable, instruction);
                                                           ^
/home/andy/Downloads/zig/src/codegen.cpp:7836:18: 0xef8d7a in do_code_gen (/home/andy/Downloads/zig/src/codegen.cpp)
        ir_render(g, fn_table_entry);
                 ^
/home/andy/Downloads/zig/src/codegen.cpp:10535:24: 0xf033c7 in codegen_build_and_link (/home/andy/Downloads/zig/src/codegen.cpp)
            do_code_gen(g);
                       ^
/home/andy/Downloads/zig/src/main.cpp:1301:39: 0xed78e4 in main0 (/home/andy/Downloads/zig/src/main.cpp)
                codegen_build_and_link(g);
                                      ^
/home/andy/Downloads/zig/src/main.cpp:1448:24: 0xed8158 in main (/home/andy/Downloads/zig/src/main.cpp)
    auto result = main0(argc, argv);
                       ^
Aborted (core dumped)