# My ROS2 minimal examples, difficulties coming from ROS1

**URL:** <https://discourse.openrobotics.org/t/my-ros2-minimal-examples-difficulties-coming-from-ros1/18705>\
**Category:** ROS General\
**Tags:** ros2\
**Created:** [January 28, 2021, 5:58pm UTC](https://discourse.openrobotics.org/t/my-ros2-minimal-examples-difficulties-coming-from-ros1/18705 "2021-01-28T17:58:57Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![iuhilnehc-ynos](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/iuhilnehc-ynos/32/9221_2.png) [@iuhilnehc-ynos](https://discourse.openrobotics.org/u/iuhilnehc-ynos)\
**Post date:** [February 3, 2021, 8:42am UTC](https://discourse.openrobotics.org/t/my-ros2-minimal-examples-difficulties-coming-from-ros1/18705/13 "2021-02-03T08:42:34Z")

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> [@tomoyafujita](#):
>
> it says it leads to crash the process, which i believe it is a bug.

I am afraid it’s not a bug. It’s just a design for ROS2 node there, and the thrown error message told us the reason.

> <https://github.com/ros2/rclcpp/blob/7c984f1a4c33f214d1ffd498dbacb64a94aaa39d/rclcpp/src/rclcpp/executor.cpp#L263>

Why don’t we use another node for creating the service client if we want to use `spin_until_future_complete` inside a node’s callback?

Please refer to somebody source code,

> <https://github.com/zygfrydw/ros2_service_issue/blob/82362ace453c53056908bcd00a5a86201f1749fa/srv_client/src/srv_client.cpp#L25-L28>

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