Multi-root with CCLS

[spaceotter]

I have an (annoying) project setup with two folders, say A and B, A has the build folder with the compilation_commands and is set up and working with CCLS. There is a separate folder B which contains some files that are part of the project. The command lsp-workspace-folders-add does not do the desired thing when I add folder B. This causes it to start a separate server with the incorrect root. If I invoke lsp manually, I can select the correct root A and it connects to the right server. How can I get files in B to automatically connect to the server for A?

[yyoncho]

Something like this should work for you:

(setq ccls-library-folders-fn (lambda (&rest _)
                                (list "/folders/that/should/be/considered/part/of/the/main/project")))

[spaceotter]

Yes, that is the behavior I want.
The behavior I see is that opening a file under bar doesn't start or use any server connection.

[yyoncho]

The behavior I see is that opening a file under bar doesn't start or use any server connection.

And what do you see when you do M-x lsp in a file under bar?

[spaceotter]

Sorry, was busy with something else and I just got back around to this.
When I do M-x lsp in a file under bar/, it tells me the file "is not part of any project" and asks to import a project root.

[spaceotter]

The menu lets me manually select /foo as the root. This doesn't work, it connects to the same ccls process as the files in /foo but ccls doesn't seem to be picking up the build arguments from /foo's compile_commands.json.

[spaceotter]

So, I modified ccls.el to set the client :library-folders-fn to the lambda directly.
Files under bar/ now connect to the foo/ server, but again don't pick up the build arguments.