idl: Fix local_file method not found for proc_macro2::Span error (solana-foundation#4187)

Author: acheroncrypto

CHANGELOG.md

@@ -26,6 +26,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - lang: Fix `declare_program!` messing up IDL errors generation ([#4126](https://github.com/solana-foundation/anchor/pull/4126)).
 - idl: Fix `address` constraint not resolving constants that have numbers in their identifiers ([#4144](https://github.com/solana-foundation/anchor/pull/4144)).
 - lang: Fix constant nested string generation in `declare_program!` ([#4158](https://github.com/solana-foundation/anchor/pull/4158)).
+- idl: Fix `local_file` method not found for `proc_macro2::Span` error ([#4187](https://github.com/solana-foundation/anchor/pull/4187)).
 
 ### Breaking
 

Cargo.lock

@@ -26,7 +26,8 @@ bs58 = "0.5"
 # `idl-build` feature only
 cargo_toml = { version = "0.19", optional = true }
 heck = "0.3"
-proc-macro2 = { version = "1", features = ["span-locations"] }
+# `Span::local_file` required by the `idl-build` feature was stabilized in `1.0.100`
+proc-macro2 = { version = "1.0.100", features = ["span-locations"] }
 quote = "1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"