Improve documentation when toolchain is not found

[stefanspringer1]

Describe the bug
Experienced this issue on Windows, but I guess this could be an issue on all platforms. When the Swift toolchain could not be detected, the user has the option to select a folder via a dialog. This does not seem to work but with no clear error message, no folder is accepted. Also it should be clearer how to find the correct folder. Is it the folder where the "swift" executable is? Setting a suitable folder directly in the setting of the extension seems to work better (but also missing guidance here).

To Reproduce
Steps to reproduce the behavior:

1. Remove the environment variables set by the Swift installer.
2. Open an SPM project in VS Code.
3. When the message that no Swift toolchain was detected, use the option to select a folder.
4. Select e.g. the folder containing swift.exe.

Expected behavior
It be clearer what folder to be selected (also for the setting), and the dialog should work or display an error message if the selected folder is not the right one.

Environment

• OS: Windowsa 11
• Swift version 6.2.1
• Visual Studio Code version: 1.106.0
• vscode-swift version: 2.14.0

[award999]

@stefanspringer1 Windows is a little more unique in that there will only be 1 install of the toolchain (can't install multiple) so as long as the PATH is set, the one and only toolchain should just be found and used without the need for selection. If you ever uninstall or install a toolchain with VSCode open, make sure to quit and restart VSCode otherwise the updated PATH won't be picked up by vscode. This Select Folder option should be more of a last resort, as we want to display all installed toolchains and if we're not then let's fix that :)

About message, we could change the "Select the folder containing Swift binaries" prompt and make it something like "Select the bin/ folder containing the Swift toolchain binaries".

Now just to confirm the title of this issue Selection the toolchain by dialog does not work, when you selected the bin folder is it not working? Or is the issue more so it wasn't clear what folder to select?

[stefanspringer1]

Now just to confirm the title of this issue Selection the toolchain by dialog does not work, when you selected the bin folder is it not working? Or is the issue more so it wasn't clear what folder to select?

@award999 Just selecting the bin folder is not enough. But I then indeed guess that PATH should just be OK on Windows, maybe then the message should be just that about PATH and the installed toolchain and restarting VS Code.

In cases it might e.g. be that VS Code was startet too early whirl the toolchain still being installed. Having those messages and dialogs (that do not work) is a little bit confusing.

Sorry I might be fussy here but if this happens with a new user of Swift, that's not good. I think it's worth the effort. Thanks!

[award999]

@stefanspringer1 should only need to select bin directory, can you run Swift: Capture Diagnostics Bundle command and send me the archive?

[award999]

@stefanspringer1 oddly enough when I was trying to do this myself, noticed swiftlang/swift#85516. So regarding When the Swift toolchain could not be detected, did you have one installed? If so then maybe this issue I stumbled upon is causing issues for you too?

[stefanspringer1]

did you have one installed?

@award999 At least I was just installing one, so it might be that I was using VS Code too early. I am not sure, I could not reproduce it. But as I understand now, giving a path on Windows is not the right thing to do, so it would be great if on Windows there were no message and no dialog to set this path. The toolchain should be installed and the PATH changed appropriately by the installation process on Windows, that should be the message.