# Trouble launching gazebo using ign command from terminal

**URL:** <https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813>\
**Category:** Gazebo Help\
**Created:** [May 31, 2022, 4:17pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813 "2022-05-31T16:17:24Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![rahelgerson94](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/rahelgerson94/32/27955_2.png) [@rahelgerson94](https://discourse.openrobotics.org/u/rahelgerson94)\
**Post date:** [May 31, 2022, 4:17pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/1 "2022-05-31T16:17:24Z")

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I am following this tutorial [https://docs.ros.org/en/foxy/Tutorial…](https://docs.ros.org/en/foxy/Tutorials/Simulators/Ignition/Setting-up-a-Robot-Simulation-Ignition.html)  
when i run the following command:  
`ign gazebo -v 4 -r visualize_lidar.sdf`

i get the following output:

```auto
The 'ign' command provides a command line interface to the ignition tools.

ign <command> [options]

List of available commands:

help: Print this help text. sdf: Utilities for SDF files. topic: Print information about topics. service: Print information about services. log: Record or playback topics. msg: Print information about messages. plugin: Print information about plugins. fuel: Manage simulation resources.

Options:

--force-version <version> Use a specific library version. --versions Show the available versions. --commands Show the available commands. Use 'ign help <command>' to print help for a command.

```

why is this happening? how can i run the example?

i installed gazebo using this tutorial.  
[https://classic.gazebosim.org/tutoria…](https://classic.gazebosim.org/tutorials?tut=ros2_installing&cat=connect_ros) i am running foxy on ubuntu 20.04 (via VMware on a mac)

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**Author:** ![Harsh\_Mahesheka\_5-Ye](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/harsh_mahesheka_5-ye/32/26916_2.png) [@Harsh\_Mahesheka\_5-Ye](https://discourse.openrobotics.org/u/Harsh_Mahesheka_5-Ye)\
**Post date:** [May 31, 2022, 5:34pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/2 "2022-05-31T17:34:41Z")

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The gazebo you installed is classical gazebo and the tutorial you are following is for ignition gazebo.You can install ignition gazebo from [https://gazebosim.org/docs](https://gazebosim.org/docs) and then ign gazebo command should run.

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**Author:** ![kakcalu13](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/kakcalu13/32/26887_2.png) [@kakcalu13](https://discourse.openrobotics.org/u/kakcalu13)\
**Post date:** [May 31, 2022, 6:11pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/3 "2022-05-31T18:11:31Z")

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What Harsh\_mahesheka\_5-ye said is perfect! I wanted to add one more thing. I’ve been using Foxy on Citadel/Fortress so if you want more information or example, [check this out!](https://github.com/gazebosim/ros_gz/tree/foxy/ros_ign_gazebo_demos/launch)

I got all sensors from there!

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**Author:** ![rahelgerson94](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/rahelgerson94/32/27955_2.png) [@rahelgerson94](https://discourse.openrobotics.org/u/rahelgerson94)\
**Post date:** [May 31, 2022, 7:54pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/4 "2022-05-31T19:54:20Z")

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i installed ignition gazebo, but when i run the command it doesn’t find the file. i get this output:

```auto
[Wrn] [ign.cc:86] Fuel world download failed because Fetch failed. Other errors
Unable to find or download file

```

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**Author:** ![rahelgerson94](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/rahelgerson94/32/27955_2.png) [@rahelgerson94](https://discourse.openrobotics.org/u/rahelgerson94)\
**Post date:** [May 31, 2022, 7:58pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/5 "2022-05-31T19:58:35Z")

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thanks for the resource @kakcalu13! what do you do with those launch.py files?  
I apologize for the ignorance, I am pretty new to ignition gazebo and ros…

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**Author:** ![kakcalu13](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/kakcalu13/32/26887_2.png) [@kakcalu13](https://discourse.openrobotics.org/u/kakcalu13)\
**Post date:** [May 31, 2022, 8:14pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/6 "2022-05-31T20:14:49Z")

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> > [Wrn] [ign.cc:86] Fuel world download failed because Fetch failed. Other errors  
> > Unable to find or download file

It just means that it can’t find the sdf file. So basically, it doesn’t know where `visualize_lidar` is or it doesn’t exist yet. You might wanna make a new file for it if it doesn’t exist.

> > thanks for the resource @kakcalu13! what do you do with those launch.py files?  
> > I apologize for the ignorance, I am pretty new to ignition gazebo and ros…

Been there! I started with Citadel and Foxy without any knowledge. 😛 So, launch allows you to load more than two files. In this case, it allowed you to load the bridge between foxy and gazebo. In my case, I used it to load rviz, bridge, ros2 program and gazebo at the same time. It’s useful for a project that needs more than one file.

BTW, if you have more questions related to Gazebo, feel free to post it in [Gazebo Answers archive](https://answers.gazebosim.org/questions/) as it involves with a deep technical. If you have a question about ROS2, use this one: [https://answers.ros.org/](https://answers.ros.org/)

This community is more likely general question without technical questions. Basically, a surface question I guess. Anyway I’m active in Answers Gazebo! I will try my best to share what I know!

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<div class="post-metadata">

**Author:** ![rahelgerson94](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/rahelgerson94/32/27955_2.png) [@rahelgerson94](https://discourse.openrobotics.org/u/rahelgerson94)\
**Post date:** [June 1, 2022, 3:31pm UTC](https://discourse.openrobotics.org/t/trouble-launching-gazebo-using-ign-command-from-terminal/48813/7 "2022-06-01T15:31:06Z")

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thank you @kakcalu13!