chore: Bump MSRV

.tool-versions

@@ -2,5 +2,5 @@ golang     1.22.0
 nodejs     16.20.2
 shellcheck 0.7.1
 yarn       1.22.22
-rust       1.74.0
+rust       1.78.0
 python     3.11.9

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Bumped MSRV to Rust 1.78.0.
+
 ## v0.5.2
 
 SCIP schema:

bindings/rust/Cargo.toml

@@ -9,9 +9,11 @@ SCIP (pronunciation: "skip") is a language-agnostic protocol for indexing source
 repository = "https://github.com/sourcegraph/scip"
 readme = "../../README.md"
 
-# We need >= 1.60.0 because the generated code uses
-# https://doc.rust-lang.org/std/vec/struct.Vec.html#method.spare_capacity_mut
-rust-version = "1.60.0"
+# We need >= 1.78.0 because: we only test against that
+# in the CI (we use protobuf-codegen in CI, and that
+# has Cargo.lock version 4, which requires Rust >= 1.78.0).
+# https://github.com/solana-foundation/anchor/issues/3392#issuecomment-2508412018
+rust-version = "1.78.0"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

cmd/scip/tests/reprolang/Cargo.toml

@@ -14,6 +14,8 @@ include = [
   "src/*",
 ]
 
+rust-version = "1.78.0"
+
 [lib]
 path = "bindings/rust/lib.rs"