Having issue to add custom variables

[lostbean]

I'm using this documentation to add a new custom chat variable, and I'm add the following configuration:

require("codecompanion").setup({
    adapters = { anthropic = "anthropic" },
    opts = { log_level = "TRACE", send_code = true, use_default_actions = true, use_default_prompts = true },
    strategies = {
        agent = { adapter = "anthropic" },
        chat = {
            adapter = "anthropic",
            variables = {
                ["git diff"] = {
                    callback = function()
                        return string.format(
                            [[
    ```diff
    %s
    ```
    ]], vim.fn.system("git diff --no-ext-diff HEAD"))
                    end,
                    description = "Share the current git diff with the LLM",
                    opts = { contains_code = true, hide_reference = true },
                },
            },
        },
        inline = { adapter = "anthropic" },
    },
})

I can see a the new variable available and add it to the chat but when I try to run it fails with this error:

E5108: Error executing lua: vim/shared.lua:0: s: expected string, got function
stack traceback:
	[C]: in function 'error'
	vim/shared.lua: in function 'validate'
	vim/shared.lua: in function 'gsplit'
	vim/shared.lua: in function 'split'
	...vim/lua/codecompanion/strategies/chat/variables/init.lua:29: in function 'resolve'
	...vim/lua/codecompanion/strategies/chat/variables/init.lua:103: in function 'parse'
	...ompanion.nvim/lua/codecompanion/strategies/chat/init.lua:590: in function 'apply_tools_and_variables'
	...ompanion.nvim/lua/codecompanion/strategies/chat/init.lua:633: in function 'submit'
	...s/start/codecompanion.nvim/lua/codecompanion/keymaps.lua:243: in function 'rhs'
	...t/codecompanion.nvim/lua/codecompanion/utils/keymaps.lua:61: in function <...t/codecompanion.nvim/lua/codecompanion/utils/keymaps.lua:58>

It's seems the variable callback does not accept functions as described in the documentation. What would be the correct way of defining this new chat variable?

[olimorris]

Thanks for this. Can confirm it's not working as documented and expected. I'll look at this in the coming days. Moved to #698