go-delve/delve · error

emulation exception

Error message

emulation exception

What it means

machTargetExcToError maps Mach exception 0x94 (EXC_EMULATION) to 'emulation exception', meaning an instruction required emulator assistance that failed (equivalent of SIGEMUL).

Source

Thrown at pkg/proc/gdbserial/gdbserver.go:2231

	copy(savedRegs.loaded, regs.loaded)
	return savedRegs, nil
}

func registerName(arch *proc.Arch, regNum uint64) string {
	regName, _, _ := arch.DwarfRegisterToString(int(regNum), nil)
	return strings.ToLower(regName)
}

func machTargetExcToError(sig uint8) error {
	switch sig {
	case 0x91:
		return errors.New("bad access")
	case 0x92:
		return errors.New("bad instruction")
	case 0x93:
		return errors.New("arithmetic exception")
	case 0x94:
		return errors.New("emulation exception")
	case 0x95:
		return errors.New("software exception")
	case 0x96:
		return errors.New("breakpoint exception")
	}
	return nil
}

func checkRosettaExpensive() error {
	if runtime.GOOS != "darwin" {
		return nil
	}
	if runtime.GOARCH != "arm64" {
		return nil
	}

	// Additionally check the output of 'uname -m' if it's x86_64 it means that
	// the shell we are running on is being emulated by Rosetta even though our

View on GitHub (pinned to a23773e6c3)

Solutions

1. Check whether you're running under Rosetta or another translation layer and test a native build.
2. Disassemble at PC to identify the faulting instruction.
3. Rebuild/upgrade dependencies that may emit obsolete instructions.
4. If persistent, report to delve/Apple with the wire log and disassembly.

if err != nil && strings.Contains(err.Error(), "emulation exception") {
    // check for translation-layer (Rosetta) issues
}

When it happens

Trigger: Target triggers an emulation fault on macOS; the stub reports Mach exception 0x94 and delve converts it into this error.

Common situations: Rare; seen with unusual instructions, binary translation layers (Rosetta), or kernels failing to emulate a legacy instruction.

Related errors

• bad access
• bad instruction
• software exception
• breakpoint exception
• could not find watchpoint at address %#x

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/11b7bd99c0a47083. Report an issue: GitHub.