Frustrating but very normal — credit histories essentially never transfer across borders, so starting from zero is the default experience for nearly every mover, not a sign you're doing something wrong. There's no universal timeline I'd trust here since it depends on what credit-building tools (a local card, on-time bill payments, sometimes a small starter loan) you have access to and how consistently you use them.
The Finance/Banking section of your destination's guide often mentions the local credit bureau system and any starter-friendly financial products — worth a look for what's actually available to you specifically rather than guessing.