`no `to_substrate_wasm_fn_return_value` in the root` when i run `cargo build` in pallet dir

Question

My rust version is :- when i was run cargo build in this dirextory: https://github.com/VegeBun-csj/Proof-Chain/tree/main/pallets/xclient

i got an error:

Answer 1

Check your std feature declaration in your pallet. There you need to ensure that for every dependency that you imported with default-features = false you have added to the std feature declaration with crate/std.

Answer 2

I encountered this recently, and the underlying issue was that I had multiple versions of the Substrate git repo being referenced in different Cargo.toml files.