catkin workspace creation in ROS - Step-by-Step Execution

Concept Flow - catkin workspace creation

Create workspace directory

↓

Create src folder inside workspace

↓

Run catkin_make in workspace

↓

Source setup.bash to update environment

↓

Workspace ready for packages

This flow shows the steps to create a catkin workspace: make folders, build with catkin_make, then source setup to use it.

Execution Sample

ROS

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws
catkin_make
source devel/setup.bash

Creates a catkin workspace directory, builds it, and sets up environment variables.

Execution Table

Step	Command	Action	Result
1	mkdir -p ~/catkin_ws/src	Create workspace and src folder	Directories ~/catkin_ws and ~/catkin_ws/src created
2	cd ~/catkin_ws	Change directory to workspace	Current directory is ~/catkin_ws
3	catkin_make	Build workspace	Build system initializes, creates build and devel folders
4	source devel/setup.bash	Update environment variables	ROS environment updated to use new workspace
5	-	Workspace ready	You can now add ROS packages inside src and build

💡 All steps complete, workspace is created and environment is set

Variable Tracker

Variable	Start	After Step 1	After Step 3	After Step 4
Directories	None	~/catkin_ws, ~/catkin_ws/src	~/catkin_ws/build, ~/catkin_ws/devel	No change
Current Directory	Home (~)	~/catkin_ws	~/catkin_ws	~/catkin_ws
Environment	Default ROS env	No change	No change	Updated to include workspace paths

Key Moments - 3 Insights

Why do we need to create the src folder inside the workspace?

The src folder is where ROS packages go; catkin_make expects this folder to find packages to build (see Step 1 in execution_table).

What does sourcing setup.bash do?

It updates your shell environment so ROS commands use the new workspace paths (see Step 4 in execution_table). Without this, ROS won't find your workspace packages.

Why run catkin_make after creating the workspace?

catkin_make initializes the workspace by creating build and devel folders and preparing the environment for packages (see Step 3).

Visual Quiz - 3 Questions

Look at the execution_table, what directories exist after Step 3?

A ~/catkin_ws/src only

B ~/catkin_ws/build and ~/catkin_ws/devel

C No directories created yet

D ~/catkin_ws/src and ~/catkin_ws/build only

💡 Hint

Check the 'Result' column for Step 3 in execution_table

At which step does the environment get updated to use the new workspace?

A Step 1

B Step 2

C Step 4

D Step 3

💡 Hint

Look for 'Update environment variables' in the 'Action' column

If you skip creating the src folder, what will happen when you run catkin_make?

A catkin_make will fail or do nothing because no packages found

B The environment will update anyway

C catkin_make will build normally

D The workspace will be created without src

💡 Hint

Refer to the importance of src folder in key_moments and Step 1

Concept Snapshot

catkin workspace creation steps:
1. mkdir -p ~/catkin_ws/src (make workspace and src folder)
2. cd ~/catkin_ws (go to workspace)
3. catkin_make (build workspace, creates build and devel)
4. source devel/setup.bash (update environment to use workspace)
Now you can add ROS packages inside src and build them.

Full Transcript

To create a catkin workspace, first make a directory named catkin_ws with a src folder inside it. Then change into the workspace directory. Run catkin_make to build the workspace; this creates build and devel folders. Finally, source the setup.bash file in devel to update your environment so ROS commands use this workspace. After these steps, you can add ROS packages inside src and build them with catkin_make.

Practice

1. What is the purpose of creating a catkin workspace in ROS?

easy

A. To organize and build your ROS packages in one place

B. To install ROS system-wide dependencies

C. To run ROS nodes without any packages

D. To update the ROS core automatically

Solution

1. Step 1: Understand what a catkin workspace is

   A catkin workspace is a folder where you keep your ROS packages organized and build them together.

2. Step 2: Identify the purpose of the workspace

   It helps you manage your own ROS projects, not system-wide installations or running nodes without packages.

3. Final Answer:

   To organize and build your ROS packages in one place -> Option A

4. Quick Check:

   Workspace = Organize & build packages [OK]

Hint: Workspace holds your ROS projects and builds them [OK]

Common Mistakes:

• Confusing workspace with system installation
• Thinking workspace runs nodes alone
• Assuming workspace updates ROS core

2. Which command correctly creates the source folder inside a catkin workspace named catkin_ws in your home directory?

easy

A. catkin_make ~/catkin_ws/src

B. mkdir ~/catkin_ws/src

C. mkdir -p ~/catkin_ws/src

D. source ~/catkin_ws/src

Solution

1. Step 1: Understand the folder creation command

   The mkdir -p command creates the full directory path, including parent folders if missing.

2. Step 2: Identify the correct command for creating src inside catkin_ws

   mkdir -p ~/catkin_ws/src uses mkdir -p ~/catkin_ws/src, which creates both catkin_ws and src if needed.

3. Final Answer:

   mkdir -p ~/catkin_ws/src -> Option C

4. Quick Check:

   Use mkdir -p for nested folders [OK]

Hint: Use mkdir -p to create nested folders at once [OK]

Common Mistakes:

• Using mkdir without -p and missing parent folder
• Confusing catkin_make with mkdir
• Trying to source a folder instead of creating it

3. After creating your catkin workspace folder and src directory, what is the output of running catkin_make inside ~/catkin_ws?

medium

A. Error: src folder missing

B. Build successful with devel and build folders created

C. No output, command ignored

D. Workspace deleted

Solution

1. Step 1: Understand what catkin_make does

   It builds the packages inside the src folder and creates devel and build folders for development and build files.

2. Step 2: Predict output after running catkin_make in a valid workspace

   Since src exists, it will build successfully and create those folders.

3. Final Answer:

   Build successful with devel and build folders created -> Option B

4. Quick Check:

   catkin_make builds workspace and creates folders [OK]

Hint: catkin_make builds and creates devel/build folders [OK]

Common Mistakes:

• Expecting error if src exists
• Thinking catkin_make deletes workspace
• Assuming no output or ignored command

4. You created a catkin workspace but forgot to source the setup file. What problem will you face?

medium

A. catkin_make will fail with syntax errors

B. The workspace will delete itself automatically

C. Your system will crash

D. ROS commands and packages from your workspace won't be recognized

Solution

1. Step 1: Understand the role of sourcing the setup file

   Sourcing devel/setup.bash sets environment variables so ROS can find your workspace packages.

2. Step 2: Identify the effect of not sourcing

   Without sourcing, ROS commands won't find your workspace packages, so they won't be recognized.

3. Final Answer:

   ROS commands and packages from your workspace won't be recognized -> Option D

4. Quick Check:

   Source setup file to use workspace [OK]

Hint: Always source setup.bash to use your workspace [OK]

Common Mistakes:

• Thinking workspace deletes itself
• Expecting catkin_make syntax errors
• Assuming system crashes

5. You want to create a new catkin workspace named my_ws in your home directory and build it. Which sequence of commands is correct?

hard

A. mkdir -p ~/my_ws/src && cd ~/my_ws && catkin_make && source devel/setup.bash

B. cd ~/my_ws && mkdir src && catkin_make && source ~/my_ws/devel/setup.bash

C. mkdir ~/my_ws && catkin_make ~/my_ws/src && source ~/my_ws/setup.bash

D. mkdir -p ~/my_ws/src && catkin_make src && source ~/my_ws/devel/setup.bash

Solution

1. Step 1: Create workspace and src folder correctly

   Use mkdir -p ~/my_ws/src to create both folders at once.

2. Step 2: Navigate to workspace and build

   Change directory to ~/my_ws and run catkin_make to build the workspace.

3. Step 3: Source the setup file

   Source devel/setup.bash inside the workspace to use the built packages.

4. Final Answer:

   mkdir -p ~/my_ws/src && cd ~/my_ws && catkin_make && source devel/setup.bash -> Option A

5. Quick Check:

   Create src, build, source setup.bash [OK]

Hint: Create src, cd workspace, catkin_make, then source setup.bash [OK]

Common Mistakes:

• Running catkin_make outside workspace folder
• Not sourcing the correct setup file
• Using wrong paths in commands