I have the following Go code:

package main

import (
    "fmt"
    "time"
)

type ticker struct {
    ticker time.Ticker
}

func main() {
    var t1 ticker
    // var err error
    go func() {
        t1.start()
        // fmt.Printf("%p\n", &err)
    }()
    defer func() {
        t1.stop()
    }()
    time.Sleep(3 * time.Second)
}

func (t *ticker) start() {
    t.ticker = *time.NewTicker(1 * time.Second)
    go func() {
        for range t.ticker.C {
            fmt.Println("Ticker ticked.")
        }
    }()
}

func (t *ticker) stop() {
    t.ticker.Stop()
}

When I run this code, I get the following error:

$ go run main.go
Ticker ticked.
Ticker ticked.
Ticker ticked.
fatal error: unexpected signal during runtime execution
[signal SIGBUS: bus error code=0x1 addr=0x1002ba730 pc=0x10024e940]

goroutine 1 gp=0x140000021c0 m=0 mp=0x100387200 [running]:
runtime.throw({0x1002c192a?, 0x1002704f0?})

...

However, if I uncomment the lines `

// var err error

and

// fmt.Printf("%p\n", &err)

the error does not occur. I don't understand why this happens. Could someone explain this behavior?

I understand that copying the value of time.Ticker is not the correct way to use and I know how to fix the code. However, I am not trying to fix the code here. I want to understand why uncommenting the line prevents the error. And what happend unser the hood.

I suspect this behavior might be related to Go's escape analysis or memory management, but I am not entirely sure. Could someone explain why this happens?

$ go version
go version go1.23.10 darwin/arm64