[Bug]: Latest version of libadalang is reporting spurious errors in vscode

[ajxs]

Environment

• OS and Version: Debian 12.
• IDE Version: Visual Studio Code 1.127.0
• Ada & SPARK Extension Version: 2026.3.202607051

Bug Summary and Reproducer

Bug Summary:

After updating to the latest version of the Ada & SPARK vscode plugin, I'm getting a lot of highlighted errors in my code (see screenshots). All of these errors seem to be the plugin having difficulties resolving symbols and types. These errors were definitely not present prior to upgrading.

Thank you for your time!

Steps to reproduce: Open project files.

Expected behavior: No incorrect errors shown.

Configuration and Logs

2026-07-07 17:54:15.575 [Ada Extension] INFO     Setting log level to: info 
2026-07-07 17:54:15.576 [Ada Extension] INFO     Starting Ada extension 
2026-07-07 17:54:15.578 [Ada Extension] INFO     Using ALS at: /home/ajxs/.vscode/extensions/adacore.ada-2026.3.202607051-linux-x64/x64/linux/ada_language_server 
2026-07-07 17:54:15.583 [Ada Extension] INFO     Using ALS at: /home/ajxs/.vscode/extensions/adacore.ada-2026.3.202607051-linux-x64/x64/linux/ada_language_server 
2026-07-07 17:54:17.081 [Ada Extension] INFO     didChangeConfiguration event received 
2026-07-07 17:54:19.245 [Ada Extension] INFO     Loading e3-testsuite: {"uri":{"$mid":1,"path":"/home/ajxs/src/straylight/testsuite.py","scheme":"file"},"python":"python"} 
2026-07-07 17:54:19.245 [Ada Extension] INFO     /home/ajxs/src/straylight/testsuite.py doesn't exist, doing nothing. 
2026-07-07 17:54:19.245 [Ada Extension] INFO     Finished starting Ada extension 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Failed to get Project.Compiler.Driver ("ada"): The queried attribute is not known 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Assuming empty target prefix 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Failed to get Project.Compiler.Driver ("ada"): The queried attribute is not known 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Assuming empty target prefix 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Failed to get Project.Compiler.Driver ("ada"): The queried attribute is not known 
2026-07-07 17:54:19.665 [Ada Extension] WARN     Assuming empty target prefix 
2026-07-07 18:29:24.252 [Ada Extension] INFO     Restarting language servers, updating the process environment first... 
2026-07-07 18:29:24.253 [Ada Extension] INFO     Restarting language server: Ada Language Server 
2026-07-07 18:29:24.343 [Ada Extension] INFO     Restarting language server: GPR Language Server 
2026-07-07 18:29:24.423 [Ada Extension] INFO     Language servers have been restarted, clearing cache and tasks 
2026-07-07 18:29:25.495 [Ada Extension] WARN     Failed to get Project.Compiler.Driver ("ada"): The queried attribute is not known 
2026-07-07 18:29:25.495 [Ada Extension] WARN     Assuming empty target prefix 
2026-07-07 18:41:36.155 [Ada Extension] INFO     didChangeConfiguration event received

Other VS Code Extensions

No response

Additional context

All of the relevant code can be found her: https://github.com/ajxs/straylight
The project file used is: https://github.com/ajxs/straylight/blob/master/src/kernel/straylight.gpr

[AnthonyLeonardoGracio]

Hello @ajxs,

This is expected, the Ada Language Server now emits semantic diagnostics, based on Libadalang. Semantic diagnostics will emit errors for each symbol that can't be resolved, helping developers to detect semantic errors without compiling.

Are you able to navigate on the unresolved symbols like Unsigned_64 by ctrl-clicking on it?

Note that you can disabled the semantic diagnostics via the VS Code settings (search for Semantic Diagnostics in the Ada & SPARK VS Code settings).

Best regards,

[ajxs]

Hello @ajxs,

This is expected, the Ada Language Server now emits semantic diagnostics, based on Libadalang. Semantic diagnostics will emit errors for each symbol that can't be resolved, helping developers to detect semantic errors without compiling.

Are you able to navigate on the unresolved symbols like Unsigned_64 by ctrl-clicking on it?

Note that you can disabled the semantic diagnostics via the VS Code settings (search for Semantic Diagnostics in the Ada & SPARK VS Code settings).

Best regards,

Thank you for your reply!
It can't resolve symbols that are obviously valid, and the diagnostics don't actually make any sense (see attached images). I'm unable to navigate on the unresolved symbols. I'd rather keep semantic diagnostics on, considering that this functionality worked correctly prior to the upgrade.

[AnthonyLeonardoGracio]

@ajxs It it can't resolve the symbols, it means that it's not able to load properly all the relevant sources of your project, particularly the symbols defined in the System package do not seem to be found by Libadalang.

Note that I have cloned your repository and try to build your project with alr, without success: are you able to build it properly on your side?

[ajxs]

@ajxs It it can't resolve the symbols, it means that it's not able to load properly all the relevant sources of your project, particularly the symbols defined in the System package do not seem to be found by Libadalang.

Note that I have cloned your repository and try to build your project with alr, without success: are you able to build it properly on your side?

It definitely builds for me, on multiple machines.
What problem are you encountering trying to build the project? Note that the only part of the project that can be built with alr is the kernel binary, with this GPR project file: src/kernel/straylight.gpr. So you'd need to run alr build in the src/kernel directory.