MATLAB: How to complete the set up for PX4 Toolchain in Linux

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I have completed the steps mentioned in Setup the PX4 Toolchain screen on my Linux computer. However, I am still unable to move forward to the next screen. On clicking the "Next >" button, I get the following error:

Best Answer

One of the reasons this issue could occur is if the default shell of your computer is not a bash shell. First, ensure that you have followed the instructions mentioned in the documentation to setup the PX4 toolchain on Linux:

https://www.mathworks.com/help/releases/R2019a/supportpkg/px4/ug/setting-px4-toolchain-linux.html

On clicking "Next >" after the installation completes successfully and if you see the above error, then check the default shell on your computer by running the following command on your terminal.

>> echo $SHELL

If the above command returns any shell (e.g., "/bin/tcsh") apart from bash shell (/bin/bash), then change the default shell to "/bin/bash".

You can also run the above command in MATLAB Command Prompt:

>> !echo $SHELL

Now the process must be launched again. Close the Hardware Setup Screens that are currently open. Open the Hardware Setup Screens again from the Add-On manager: Home > Add-Ons > Manage Add-Ons. Click the Set Up button "Next >" in the Embedded Coder Support Package for PX4 Autopilots. This should solve the issue and you will be able to move forward with the screens.

Related Solutions

MATLAB: Does the PX4 Support Package Setup not recognize the installed Ubuntu distribution on Windows 10

This may happen if the call to bash.exe fails from the Windows Command Prompt (CMD). You can verify this by entering the following command at the MATLAB prompt:

>> system('bash')
The system cannot find the path specified.

Note that along with Ubuntu bash/Windows System for Linux, there is another way to install PX4 toolchain - by using PX4 cygwin toolchain (which is the preferred way). This is officially supported as part of hardware setup screens from R2019b onwards. For R2019a, we have a documented way of how to use it.

So the following are the options in decreasing order of preference.

Upgrade to R2019b, and use the Hardware Setup screens which will guide you to setup the cygwin toolchain and firmware.
If upgrading to R2019b is not possible, see the below R2019a documentation link which will help install the PX4 cygwin toolchain: https://www.mathworks.com/help/releases/R2019a/supportpkg/px4/ug/px4-using-cygwin.html
If you want to use the Ubuntu bash/Windows System for Linux only, please contact your IT helpdesk to find out why it is not possible to call bash.exe from the Windows Command Prompt on your machine.

MATLAB: Using the “system” or “bang” (“!”) command on Linux returns an output of “127”

It appears that "127" is a Linux Terminal exit flag that indicates that a command could not be found. It is possible that there is a 'PATH' or 'SHELL' variable issue between MATLAB and the Linux shell. Please try the following workarounds:

1. Try the following in order to set the MATLAB path to the Linux environment path. Then, try the "system" command:

>> PATH = getenv('PATH');
>> setenv('PATH', [PATH ':/usr/local/desiredpathtoexe']);
>> [status, cmdout] = system('pwd')

2. If the above does not resolve the issue, then there could be an issue with the 'SHELL' variable. First, we need to determine the system's default shell, as well as the shell currently being used in the Terminal:

a. Find the default startup shell:

$ echo $SHELL

b. Find the shell currently used in the Terminal

$ echo $0
$ ps -p $$

c. Find the location of that shell's executable. For example, for Bash, the following might output '/bin/bash':

$ which bash

3. Now, find the shell being used by MATLAB:

>> sh = getenv('SHELL')

If this is not the same as the shell used in the Terminal, you can use "setenv" to set it to your desired shell location. Using Bash as an example:

>> setenv('SHELL','/bin/bash')

4. If the issue still persists, make sure that the $SHELL environment variable is set to the value you want before opening MATLAB. Using Bash as an example:

$ export $SHELL=/bin/bash

5. If the issue is still not resolved, and the system default shell and current Terminal shell are different, you can change the system default shell to the desired shell with the following command. Using Bash as an example:

$ chsh -s /bin/bash your_username

This might require logging out and logging in so that the change applies.

6. If you still experience issues, check your .bashrc file or other shell startup files for anything that could be causing issues.

Best Answer

Related Solutions

MATLAB: Does the PX4 Support Package Setup not recognize the installed Ubuntu distribution on Windows 10

MATLAB: Using the “system” or “bang” (“!”) command on Linux returns an output of “127”

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