Remove the print_debug and build-metadata cargo features

CHANGELOG.md

@@ -12,6 +12,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 * **Breaking:** Generated libc bindings use `usize` for `size_t` arguments and return values, including `strlen` and `memcpy`. Rust callers that use `u64` or `c_ulong` need explicit conversions. The C ABI is unchanged.
 
 ### Removed
+* **Breaking:** The `print_debug` cargo feature and the exported `hyperlight_host::debug!` macro. Use `tracing::debug!` with a subscriber.
+* **Breaking:** The `build-metadata` cargo feature. A library should not log build details, and for crates.io users its git fields were always empty. Applications can log build details with their own tooling.
 
 ### Fixed
 

Justfile

@@ -112,8 +112,8 @@ test-like-ci config=default-target hypervisor="kvm":
     @# with default features
     just test {{config}}
 
-    @# with only one driver enabled + build-metadata
-    just test {{config}} build-metadata,{{ if hypervisor == "mshv3" {"mshv3"} else {"kvm"} }}
+    @# with only one driver enabled
+    just test {{config}} {{ if hypervisor == "mshv3" {"mshv3"} else {"kvm"} }}
 
     @# with hw-interrupts enabled (+ explicit driver on Linux)
     {{ if os() == "linux" { if hypervisor == "mshv3" { "just test " + config + " mshv3,hw-interrupts" } else { "just test " + config + " kvm,hw-interrupts" } } else { "just test " + config + " hw-interrupts" } }}
@@ -375,7 +375,6 @@ miri-tests: (ensure-cargo-nextest) (ensure-nightly-miri)
 check:
     {{ cargo-cmd }} check  {{ target-triple-flag }}
     {{ cargo-cmd }} check -p hyperlight-host --features crashdump  {{ target-triple-flag }}
-    {{ cargo-cmd }} check -p hyperlight-host --features print_debug  {{ target-triple-flag }}
     {{ cargo-cmd }} check -p hyperlight-host --features gdb  {{ target-triple-flag }}
     {{ cargo-cmd }} check -p hyperlight-host --features trace_guest,mem_profile  {{ target-triple-flag }}
     {{ cargo-cmd }} check -p hyperlight-host --features hw-interrupts  {{ target-triple-flag }}
@@ -587,8 +586,8 @@ coverage-run hypervisor="kvm": ensure-cargo-llvm-cov
     # tests with default features (all drivers; skip stress tests — too slow under instrumentation)
     cargo +{{nightly-toolchain}} test {{ coverage-packages }} --tests -- --skip stress_test
 
-    # tests with single driver + build-metadata
-    cargo +{{nightly-toolchain}} test {{ coverage-packages }} --no-default-features --features build-metadata,{{ if hypervisor == "mshv3" { "mshv3" } else { "kvm" } }} --tests -- --skip stress_test
+    # tests with single driver
+    cargo +{{nightly-toolchain}} test {{ coverage-packages }} --no-default-features --features {{ if hypervisor == "mshv3" { "mshv3" } else { "kvm" } }} --tests -- --skip stress_test
 
     # isolated tests (require running separately due to global state)
     cargo +{{nightly-toolchain}} test -p hyperlight-host --lib -- sandbox::uninitialized::tests::test_log_trace --exact --ignored

docs/how-to-run-coverage.md

@@ -98,8 +98,8 @@ We use [cargo-llvm-cov](https://github.com/taiki-e/cargo-llvm-cov) over alternat
 
 The `coverage-run` recipe mirrors the `test-like-ci` + `run-examples-like-ci` workflows by running all test phases and examples with different feature combinations:
 
-1. **Default features** — all drivers enabled (kvm + mshv3 + build-metadata)
-2. **Single driver** — only one hypervisor driver + build-metadata
+1. **Default features** — all drivers enabled (kvm + mshv3)
+2. **Single driver** — only one hypervisor driver
 3. **Isolated tests** — tests that require running separately due to global state
 4. **Integration tests** — including `executable_heap` feature
 5. **Crashdump** — tests + example with the `crashdump` feature enabled

hack/clippy-package-features.sh

@@ -37,7 +37,7 @@ fi
 EXCLUDED_FEATURES=("${REQUIRED_FEATURES[@]}")
 
 if [[ -n "${TARGET_TRIPLE}" && "$TARGET_TRIPLE" =~ aarch64 ]] || [[ -z "${TARGET_TRIPLE}" && "$(uname -m)" = "aarch64" ]]; then
-    EXCLUDED_FEATURES+=("crashdump" "trace_guest" "mem_profile" "hw-interrupts" "gdb" "i686-guest" "nanvix-unstable")
+    EXCLUDED_FEATURES+=("crashdump" "trace_guest" "mem_profile" "hw-interrupts" "gdb")
 fi
 
 # Get all features for the package (excluding default and required features)

src/hyperlight_common/Cargo.toml

@@ -4,7 +4,7 @@
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
 homepage.workspace = true
 repository.workspace = true
 readme.workspace = true
 description = """
@@ -35,7 +35,7 @@
 fuzzing = ["dep:arbitrary"]
 trace_guest = []
 mem_profile = []
-std = ["thiserror/std", "log/std", "tracing/std"]
+std = ["thiserror/std", "log/std", "tracing?/std"]
 
 [dev-dependencies]
 criterion = "0.8.1"

src/hyperlight_guest_bin/Cargo.toml

@@ -4,7 +4,7 @@
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
 homepage.workspace = true
 repository.workspace = true
 readme.workspace = true
 description = """
@@ -15,7 +15,7 @@
 [features]
 default = ["libc", "macros"]
 libc = ["dep:hyperlight-libc"] # compile libc from picolibc
-trace_guest = ["hyperlight-common/trace_guest", "hyperlight-guest/trace_guest", "hyperlight-guest-tracing/trace"]
+trace_guest = ["hyperlight-guest/trace_guest", "hyperlight-guest-tracing/trace"]
 mem_profile = ["hyperlight-common/mem_profile"]
 macros = ["dep:hyperlight-guest-macro", "dep:linkme"]
 

src/hyperlight_host/Cargo.toml

@@ -4,7 +4,7 @@
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
 homepage.workspace = true
 repository.workspace = true
 readme.workspace = true
 description = """
@@ -122,16 +122,13 @@
 [build-dependencies]
 anyhow = { version = "1.0.102" }
 cfg_aliases = "0.2.1"
-built = { version = "0.8.1", optional = true, features = ["chrono", "git2"] }
 bindgen = { version = "0.72", features = ["prettyplease"] }
 cc = "1.2"
 
 [features]
-default = ["kvm", "mshv3", "hvf", "build-metadata"]
+default = ["kvm", "mshv3", "hvf"]
 function_call_metrics = []
 executable_heap = []
-# This feature enables printing of debug information to stdout in debug builds
-print_debug = []
 # Dumps the VM state to a file on unexpected errors or crashes. The path of the file will be printed on stdout and logged.
 crashdump = ["dep:chrono", "dep:elfcore"]
 trace_guest = ["dep:opentelemetry", "dep:tracing-opentelemetry", "dep:hyperlight-guest-tracing", "hyperlight-common/trace_guest"]
@@ -143,7 +140,6 @@
 # This enables easy debug in the guest
 gdb = ["dep:gdbstub", "dep:gdbstub_arch"]
 fuzzing = ["hyperlight-common/fuzzing"]
-build-metadata = ["dep:built"]
 
 [[bench]]
 name = "benchmarks"

src/hyperlight_host/build.rs

@@ -2,8 +2,6 @@
 // Copyright 2025 The Hyperlight Authors.
 
 use anyhow::{Context, Result};
-#[cfg(feature = "build-metadata")]
-use built::write_built_file;
 
 fn main() -> Result<()> {
     // re-run the build if this script is changed (or deleted!),
@@ -155,8 +153,6 @@ fn main() -> Result<()> {
         mshv3: { all(feature = "mshv3", target_os = "linux") },
         hvf: { all(feature = "hvf", target_os = "macos") },
         crashdump: { all(feature = "crashdump", target_arch = "x86_64") },
-        // print_debug feature is aliased with debug_assertions to make it only available in debug-builds.
-        print_debug: { all(feature = "print_debug", debug_assertions) },
         // the gdb feature (only temporarily!) needs to use
         // writable/un-shared snapshot memories.
         unshared_snapshot_mem: { gdb },
@@ -176,8 +172,5 @@ fn main() -> Result<()> {
         readable_shared_mem: { any(gdb, all(feature = "mem_profile", not(unshared_snapshot_mem))) },
     }
 
-    #[cfg(feature = "build-metadata")]
-    write_built_file()?;
-
     Ok(())
 }

src/hyperlight_host/src/lib.rs

@@ -26,16 +26,6 @@
 #![cfg_attr(not(any(test, debug_assertions)), warn(clippy::expect_used))]
 #![cfg_attr(not(any(test, debug_assertions)), warn(clippy::unwrap_used))]
 
-#[cfg(feature = "build-metadata")]
-use std::sync::Once;
-
-#[cfg(feature = "build-metadata")]
-/// The `built` crate is used to generate a `built.rs` file that contains
-/// information about the build environment. This information is used to
-/// populate the `built_info` module, which is re-exported here.
-pub(crate) mod built_info {
-    include!(concat!(env!("OUT_DIR"), "/built.rs"));
-}
 /// Dealing with errors, including errors across VM boundaries
 pub mod error;
 /// Wrappers for host and guest functions.
@@ -135,67 +125,3 @@ macro_rules! log_then_return {
            return Err(__err);
     };
 }
-
-/// Same as tracing::debug!, but will additionally print to stdout if the print_debug feature is enabled
-#[macro_export]
-macro_rules! debug {
-    ($($arg:tt)+) =>
-    {
-        #[cfg(print_debug)]
-        println!($($arg)+);
-        tracing::debug!($($arg)+);
-    }
-}
-
-// LOG_ONCE is used to log information about the crate version once
-#[cfg(feature = "build-metadata")]
-static LOG_ONCE: Once = Once::new();
-
-#[cfg(feature = "build-metadata")]
-pub(crate) fn log_build_details() {
-    use tracing::info;
-    LOG_ONCE.call_once(|| {
-        info!("Package name: {}", built_info::PKG_NAME);
-        info!("Package version: {}", built_info::PKG_VERSION);
-        info!("Package features: {:?}", built_info::FEATURES);
-        info!("Target triple: {}", built_info::TARGET);
-        info!("Optimization level: {}", built_info::OPT_LEVEL);
-        info!("Profile: {}", built_info::PROFILE);
-        info!("Debug: {}", built_info::DEBUG);
-        info!("Rustc: {}", built_info::RUSTC);
-        info!("Built at: {}", built_info::BUILT_TIME_UTC);
-        match built_info::CI_PLATFORM.unwrap_or("") {
-            "" => info!("Not built on  a CI platform"),
-            other => info!("Built on : {}", other),
-        }
-        match built_info::GIT_COMMIT_HASH.unwrap_or("") {
-            "" => info!("No git commit hash found"),
-            other => info!("Git commit hash: {}", other),
-        }
-
-        let git = match built_info::GIT_HEAD_REF.unwrap_or("") {
-            "" => {
-                info!("No git head ref found");
-                false
-            }
-            other => {
-                info!("Git head ref: {}", other);
-                true
-            }
-        };
-        match built_info::GIT_VERSION.unwrap_or("") {
-            "" => info!("No git version found"),
-            other => info!("Git version: {}", other),
-        }
-        match built_info::GIT_DIRTY.unwrap_or(false) {
-            true => info!("Repo had uncommitted changes"),
-            false => {
-                if git {
-                    info!("Repo had no uncommitted changes")
-                } else {
-                    info!("No git repo found")
-                }
-            }
-        }
-    });
-}

src/hyperlight_host/src/sandbox/trace/context.rs

@@ -347,7 +347,7 @@ impl TraceContext {
 
     pub(crate) fn setup_guest_trace(&mut self, ctx: Context) {
         if self.start_instant.is_none() {
-            crate::debug!("Guest Start Epoch set");
+            tracing::debug!("Guest Start Epoch set");
             self.start_wall = Some(SystemTime::now());
             self.start_tsc = Some(hyperlight_guest_tracing::invariant_tsc::read_tsc());
             self.start_instant = Some(std::time::Instant::now());

src/hyperlight_host/src/sandbox/uninitialized.rs

@@ -14,8 +14,6 @@ use super::snapshot::Snapshot;
 use super::uninitialized_evolve::initialize_sandbox;
 use crate::func::host_functions::{HostFunction, register_host_function};
 use crate::func::{ParameterTuple, SupportedReturnType};
-#[cfg(feature = "build-metadata")]
-use crate::log_build_details;
 use crate::mem::memory_region::{DEFAULT_GUEST_BLOB_MEM_FLAGS, MemoryRegionFlags};
 use crate::mem::mgr::SandboxMemoryManager;
 use crate::mem::shared_mem::{ExclusiveSharedMemory, SharedMemory};
@@ -142,9 +140,6 @@ impl UninitializedSandbox {
     //
     // This is ok for now as this is not a public function
     fn from_snapshot(snapshot: Arc<Snapshot>, cfg: Option<SandboxConfiguration>) -> Result<Self> {
-        #[cfg(feature = "build-metadata")]
-        log_build_details();
-
         // hyperlight is only supported on Windows 11 and Windows Server 2022 and later
         #[cfg(target_os = "windows")]
         check_windows_version()?;
@@ -165,7 +160,7 @@ impl UninitializedSandbox {
             pending_file_mappings: Vec::new(),
         };
 
-        crate::debug!("Sandbox created:  {:#?}", sandbox);
+        tracing::debug!("Sandbox created:  {:#?}", sandbox);
 
         Ok(sandbox)
     }
@@ -794,7 +789,6 @@ mod tests {
     ///    our subscriber's `Interest::sometimes()`
     /// 3. Clear recorded state and run the real test
     #[test]
-    #[cfg(feature = "build-metadata")]
     fn test_trace_trace() {
         use hyperlight_testing::tracing_subscriber::TracingSubscriber;
         use tracing::Level;
@@ -905,7 +899,6 @@ mod tests {
     #[ignore]
     // Tests that traces are emitted as log records when there is no trace
     // subscriber configured.
-    #[cfg(feature = "build-metadata")]
     fn test_log_trace() {
         use std::path::PathBuf;
 

src/hyperlight_libc/Cargo.toml

@@ -5,7 +5,7 @@
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
 homepage.workspace = true
 repository.workspace = true
 readme = "README.md"
 description = """
@@ -13,9 +13,6 @@
 It builds the picolibc library and generates bindings to the libc types and functions.
 """
 
-[features]
-default = []
-
 [dependencies]
 
 [lints]

src/tests/rust_guests/dummyguest/Cargo.toml

@@ -11,4 +11,4 @@ hyperlight-common = { path = "../../../hyperlight_common", default-features = fa
 [features]
 default = []
 trace_guest = ["hyperlight-guest-bin/trace_guest"]
-mem_profile = ["hyperlight-common/mem_profile", "hyperlight-guest-bin/mem_profile"]
+mem_profile = ["hyperlight-guest-bin/mem_profile"]

src/tests/rust_guests/simpleguest/Cargo.toml

@@ -13,6 +13,6 @@ tracing = { version = "0.1.41", default-features = false, features = ["log", "at
 
 [features]
 default = []
-trace_guest = ["hyperlight-guest-bin/trace_guest", "hyperlight-guest/trace_guest", "hyperlight-guest-tracing/trace"]
-mem_profile = ["hyperlight-common/mem_profile", "hyperlight-guest-bin/mem_profile"]
+trace_guest = ["hyperlight-guest-bin/trace_guest"]
+mem_profile = ["hyperlight-guest-bin/mem_profile"]
 

src/tests/rust_guests/witguest/Cargo.toml

@@ -12,5 +12,5 @@ spin = "0.12.0"
 
 [features]
 default = []
-trace_guest = ["hyperlight-guest-bin/trace_guest", "hyperlight-guest/trace_guest"]
-mem_profile = ["hyperlight-common/mem_profile", "hyperlight-guest-bin/mem_profile"]
+trace_guest = ["hyperlight-guest-bin/trace_guest"]
+mem_profile = ["hyperlight-guest-bin/mem_profile"]