Ada Extension cannot find compiler chain in WSL2 (22.04 Ubuntu)

[moverby44]

Environment is WSL2 on Windows 11 2H22. Distro is Ubuntu Jammy.
I did a sudo apt install gnat gprbuild
Both completed with success.
I have the ALS installed with version 23.0.17.

I can manually compile with gprbuild the hello_world example from the ALS tutorial.
However, I'm getting no language server behavior and it is complaining that it cannot find a toolchain. If I open a terminal from VS Code and do gnatls, I see the expected output. I can also do a gprbuild for the .gpr file from the hello_world example and it compiles correctly and the program runs normally. However, the language server insists that there is no tool chain.

Suggestions? Or is this a bug?

[moverby44]

I eventually get this message as well:
The project was loaded, but no Ada runtime found. Please check the installation of the Ada compiler.

I should reinforce, from a VS code terminal window, I can gprbuild the file as well as execute the resulting binary.

[reznikmm]

Did you follow Get started using Visual Studio Code with Windows Subsystem for Linux?

[moverby44]

Yes I have. VS Code works properly for other language servers (C++ as an example).
I even just tested this on a fresh laptop with a new WSL2 install of ada. I walked through the steps in the linked page.

I also, walked through the steps here:
https://github.com/AdaCore/ada_language_server/wiki/Getting-Started

After several minutes it complains about no ada toolchain.
A gprbuild from the command line succeeds (from a VS code terminal even).

Screen shots attached.

[moverby44]

Just to make sure this wasn't a specific WSL2 problem. I also spun up an x86_64 EC2 instance clean and installed everything and did a remote SSH connection through code to the EC2 instance and I'm getting basically the same error (although it happens much faster).

[brownts]

This is likely due to a version mismatch between the GNAT and GCC versions you have installed. I had pretty much the same problem recently on Ubuntu. By default, sudo apt install gnat will install gnat-10. GCC defaults to gcc-11 on Ubuntu 22.04. ALS can't find the run-time when you have a mismatched GNAT/GCC installation like this. Try installing gnat-11, or whatever version matches your GCC installation (i.e., gcc --version).

[reznikmm]

Could you try to install gnat_native and gprbuild with Alire and try with them?

[moverby44]

I will try both suggestions. I'm not sure about the gcc version, I thought on my clean install gnat forced a load of a matching gcc, but I'll check.

I'll also try Alire, but unfortunately on WSL2 anyway when I tried Alire before I gave up as the performance was horrible. A hello world app took 4 minutes to build. The same code with gprbuild took a second. But I will try the combination as well.

[moverby44]

Bingo. I think we have a winner. @brownts nailed it. apt removed everything and did gcc with gnat-11 and it works on ec2. I'll try WSL2 next.

[moverby44]

Also verified that it fixes WSL2.

Should this get added to the Ada language server front page?

[reznikmm]

We have added more diagnostic messages in the extension 23.0.18. While we seek to better support Debian/Ubuntu Ada toolchains, I think, it worth to mention this bug on Ada language server front page, indeed.