Function make_references_string 

fn make_references_string<'a>(
    ty: &str,
    references: impl IntoIterator<Item = StorePathRef<'a>>,
    self_ref: bool,
) -> String

This contains the Nix logic to create “text hash strings”, which are used in builtins.toFile, as well as in Derivation Path calculation.

A text hash is calculated by concatenating the following fields, separated by a ::

• text
• references, individually joined by :
• the nix_hash_string representation of the sha256 digest of some contents
• the value of storeDir
• the name