Only enable dhat dependency if feature is enabled

packages/vm/Cargo.toml

@@ -20,8 +20,8 @@ staking = ["cosmwasm-std/staking"]
 stargate = ["cosmwasm-std/stargate"]
 # Use cranelift backend instead of singlepass. This is required for development on Windows.
 cranelift = ["wasmer/cranelift"]
-# For heap profiling. Used in examples.
-dhat-heap = []
+# For heap profiling. Only used in "memory" example.
+dhat-heap = ["dep:dhat"]
 
 [lib]
 # See https://bheisler.github.io/criterion.rs/book/faq.html#cargo-bench-gives-unrecognized-option-errors-for-valid-command-line-options
@@ -45,6 +45,9 @@ thiserror = "1.0.26"
 wasmer = { version = "=4.2.5", default-features = false, features = ["cranelift", "singlepass"] }
 wasmer-middlewares = "=4.2.5"
 strum = { version = "0.25.0", default-features = false, features = ["derive"] }
+# For heap profiling. Only used in "memory" example. This has to be a non-dev dependency
+# because cargo currently does not support optional dev-dependencies.
+dhat = { version = "0.3.2", optional = true }
 
 # Dependencies that we do not use ourself. We add those entries
 # to bump the min version of them.
@@ -67,7 +70,6 @@ clap = "4"
 rand = "0.8"
 leb128 = "0.2"
 target-lexicon = "0.12"
-dhat = "0.3.2"
 time = { version = "0.3.28", features = ["formatting"] }
 
 [[bench]]
@@ -77,7 +79,7 @@ harness = false
 [[example]]
 name = "memory"
 path = "examples/memory.rs"
-required-features = []
+required-features = ["dhat-heap"]
 
 [profile.release]
 debug = 1

packages/vm/examples/memory.rs

@@ -12,7 +12,6 @@ use cosmwasm_vm::{
     Size,
 };
 
-#[cfg(feature = "dhat-heap")]
 #[global_allocator]
 static ALLOC: dhat::Alloc = dhat::Alloc;