Matlab rosinit error:Could not install the required Python packages.

Hi:

I want to use ros and matlab to realize co-simulation, but when I input rosinit in matlab, the following error appears:

matlab 2020b,updata6

Could not install the required Python packages. System error message:

'"C:\Users\t\AppData\Roaming\MathWorks\MATLAB\R2020b\ros1\win64\venv\Scripts\activate"'It is not an internal or external command, nor is it an executable program or batch file.

. Use pyenv function to set the path to the Python executable and retry the command.

I would appreciate your help.

[Jagadeesh Konakalla]

Hi ,

Can you please run the following commands in MATLAB and let me know if it works.

pyenv('Version',<path to Python 2.7>);
ros.internal.createOrGetLocalPython(true);
rosinit; 

Thanks,

Jagadeesh K.

[庆 苏]

Thank you very much for your reply,but I've solved this problem. This problem occurred because I used matlab2020b at the beginning, and there were problems with the ros toolkit before update2. Therefore, when I used the rosinit command, the ros1 folder was generated, but the subsequent packages could not be downloaded. After that, I updated and set up update6. Since the ros1 folder was generated before, I failed to regenerate it correctly this time, which caused the subsequent packages to fail to download. Deleting the original ros1 and this problem resolved.

[sven lack]

Hi, thank you very much for sharing your solution. I had a similar problem. After the command "rosinit" the following error message came up:

>> rosinit
Launching ROS Core...
Could not create Python virtual environment.
'C:\Users\<user_name>\AppData\Roaming\MathWorks\MATLAB\R2020b\ros1\win64\venv\Scripts\python.exe' is not found. Verify installation of
Python in your system and re-create the Python virtual environment.

After some research, I came across the answer from B. W. Brokaw.

could-not-create-python-virtual-environment#answer_682155

His tip solved the problem with the "virtual python enviornment" but led to a different error message:

>> rosinit
Launching ROS Core...
Adding required Python packages to virtual environment..Done.
Could not install the required Python packages. System error message: usage: python -m ensurepip [-h] [--version] [-v] [-U] [--user]
[--root ROOT]  [--altinstall] [--default-pip]
python -m ensurepip: error: unrecognized arguments: --no-default-pip. Use pyenv function to set the path to the Python executable and retry the command.

Then I followed your hint and deleted the "C:\Users\<user_name>\AppData\Roaming\MathWorks\MATLAB\R2020b\ros1" folder. After that, the rosinit command worked without problems. Thank you!

Answer 1

[Jagadeesh Konakalla]

https://de.mathworks.com/matlabcentral/answers/789104-could-not-create-python-virtual-environment#answer_682155