libmicroros.a', needed by 'int32_publisher.elf', missing and no known rule to make it

[Usama-Arshad16]

int32_publisher example not building

• Hardware description: I was trying to build it for esp32
• Installation type: ROS2 foxy with micro_ros_espidf_component
• Version or commit hash: microros foxy

Steps to reproduce the issue

I have Ros Foxy installed on my PC. In order to use microros with esp32, I first cloned esp_idf and then I cloned micro_ros_espidf_component repo.
These are the commands i followed

• . $IDF_PATH/export.sh
• cd examples/int32_publisher
• idf.py set-target esp32
• idf.py build

Expected behavior

I was expecting it to build successfully.

Actual behavior

But Actually it was giving me error shown below

Additional information

[liamhan0905]

I'm getting the same error

[nilseuropa]

Me too,but on humble branch.

[liamhan0905]

@nilseuropa what branch have you tried that worked? Since humble is supported, I thought it would work. I just tried using the foxy branch but getting the same error

[UsamaArshad16]

Please someone solve this.
I also tried this using docker, but the error stays the same

[glmnet]

I was getting this error then I run

cd ~/esp/esp-idf
source ./export.sh
pip3 install catkin_pkg lark-parser empy colcon-common-extensions

then I clean build and it worked, seems like the source before pip3 install didn't work when I did it first time.

[dgarcu]

I have also solved it with the solution provided by @glmnet 😄

[2b-t]

I had the very same issue. My issue might be very specific but in my case the problem was my .gitconfig in combination with a YubiKey hardware identification device. A while back I had configured an insteadOf rule for Git so that it would use SSH for cloning any Github repository instead of HTTPS.

$ cat /home/$USER/.gitconfig
[user]
	signingKey = <my_gpg_key>
	name = <my_name>
	email = <my_email>
[commit]
	gpgsign = true
[gpg]
	program = gpg
[url "ssh://[email protected]/"]
	insteadOf = https://github.com/

The SSH keys are saved on my Yubikey ($ ssh-add -K) and I need to confirm by tapping my YubiKey.

After executing $ idf.py set-target <target_type>, various repositories should be pulled from Github and libmicroros.a should be compiled. As this would fail silently /micro_ros_espidf_component/micro_ros_src/build would be almost empty and /micro_ros_espidf_component/libmicroros.a would not exist at all. Furthermore also building with the Docker would fail as my .gitconfig on the host system would be copied inside my Docker, resulting in the very same issue.
Simply deleting the entire .gitconfig inside my Docker with $ rm /home/$USER/.gitconfig (or alternatively deleting just this rule) solved the issue and I was able to build and flash micro-ROS onto my ESP32-C3.