More information in --version

Cargo.toml

@@ -21,6 +21,8 @@ version = "0.2.0"
 [workspace.dependencies]
 re_analytics = { path = "crates/re_analytics", version = "0.2.0" }
 re_arrow_store = { path = "crates/re_arrow_store", version = "0.2.0" }
+re_build_build_info = { path = "crates/re_build_build_info", version = "0.2.0" }
+re_build_info = { path = "crates/re_build_info", version = "0.2.0" }
 re_data_store = { path = "crates/re_data_store", version = "0.2.0" }
 re_error = { path = "crates/re_error", version = "0.2.0" }
 re_format = { path = "crates/re_format", version = "0.2.0" }
@@ -69,6 +71,7 @@ polars-ops = "0.27.1"
 puffin = "0.14"
 reqwest = { version = "0.11", default-features = false }
 thiserror = "1.0"
+time = "0.3"
 tokio = "1.24"
 wgpu = { version = "0.15", default-features = false }
 wgpu-core = { version = "0.15", default-features = false }

crates/re_analytics/Cargo.toml

@@ -18,6 +18,7 @@ all-features = true
 
 [dependencies]
 # Internal dependencies:
+re_build_info.workspace = true
 re_log.workspace = true
 
 # External dependencies:
@@ -45,5 +46,4 @@ tracing-subscriber = "0.3"
 
 
 [build-dependencies]
-anyhow.workspace = true
-glob = "0.3"
+re_build_build_info.workspace = true

crates/re_analytics/build.rs

@@ -1,74 +1,3 @@
-use std::process::Command;
-
-// Situations to consider
-// ----------------------
-//
-// # Using the published crate
-//
-// The published crate carries its version around, which in turns gives us the git tag, which makes
-// the commit hash irrelevant.
-// We still need to compute _something_ so that we can actually build, but that value will be
-// ignored when the crate is built by the end user anyhow.
-//
-// # Working directly within the workspace
-//
-// When working within the workspace, we can simply try and call `git` and we're done.
-//
-// # Using an unpublished crate (e.g. `path = "..."` or `git = "..."` or `[patch.crates-io]`)
-//
-// In these cases we may or may not have access to the workspace (e.g. a `path = ...` import likely
-// will, while a crate patch won't).
-//
-// This is not an issue however, as we can simply try and see what we get.
-// If we manage to compute a commit hash, great, otherwise we still have the crate version to
-// fallback on.
-
 fn main() {
-    // target triple
-    println!(
-        "cargo:rustc-env=__RERUN_TARGET_TRIPLE={}",
-        std::env::var("TARGET").unwrap()
-    );
-
-    match git_hash() {
-        Ok(git_hash) => {
-            println!("cargo:rustc-env=__RERUN_GIT_HASH={git_hash}");
-            for path in glob::glob("../../.git/refs/heads/**").unwrap() {
-                println!("cargo:rerun-if-changed={}", path.unwrap().to_string_lossy());
-            }
-        }
-        // NOTE: In 99% of cases, if `git_hash` failed it's because we're not in a git repository
-        // to begin with, which happens because we've imported the published crate from crates.io.
-        //
-        // When that happens, we want the commit hash to be the git tag that corresponds to the
-        // published version, so that one can always easily checkout the `git_hash` field in the
-        // analytics.
-        //
-        // Example of unlikely cases where the above does not hold:
-        // - `git` is not installed
-        // - the user downloaded rerun as a tarball and then imported via a `path = ...` import
-        // - others?
-        Err(_) => println!(
-            "cargo:rustc-env=__RERUN_GIT_HASH=v{}",
-            env!("CARGO_PKG_VERSION")
-        ),
-    }
-}
-
-fn git_hash() -> anyhow::Result<String> {
-    let output = Command::new("git").args(["rev-parse", "HEAD"]).output()?;
-
-    let git_hash = String::from_utf8(output.stdout)?;
-    let git_hash = git_hash.trim();
-    if git_hash.is_empty() {
-        anyhow::bail!("empty commit hash");
-    }
-
-    let clean = Command::new("git")
-        .args(["diff-files", "--quiet"])
-        .output()?
-        .status
-        .success();
-
-    Ok(format!("{}{}", git_hash, if clean { "" } else { "-dirty" }))
+    re_build_build_info::export_env_vars();
 }

crates/re_analytics/src/cli.rs

@@ -116,6 +116,9 @@ const DETAILS: &str = "
 ";
 
 pub fn print_details() {
-    let git_hash = env!("__RERUN_GIT_HASH").replace("-dirty", "");
-    eprintln!("{}", DETAILS.replace("GIT_HASH", &git_hash));
+    let build_info = re_build_info::build_info!();
+    eprintln!(
+        "{}",
+        DETAILS.replace("GIT_HASH", &build_info.git_hash_or_tag())
+    );
 }

crates/re_analytics/src/lib.rs

@@ -52,17 +52,6 @@ use time::OffsetDateTime;
 
 // ----------------------------------------------------------------------------
 
-/// What target triplet (os, cpu) `re_analytics` was compiled for.
-pub const TARGET_TRIPLET: &str = env!("__RERUN_TARGET_TRIPLE");
-
-/// What git hash of the Rerun repository we were compiled in.
-///
-/// If we are not in the Rerun repository, this will be set
-/// to the `re_analytics` crate version (`CARGO_PKG_VERSION`) instead.
-pub const GIT_HASH: &str = env!("__RERUN_GIT_HASH");
-
-// ----------------------------------------------------------------------------
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 pub enum EventKind {
     /// Append a new event to the time series associated with this analytics ID.

crates/re_build_build_info/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "re_build_build_info"
+authors.workspace = true
+description = "build.rs helpers for generating build info"
+edition.workspace = true
+homepage.workspace = true
+include.workspace = true
+license.workspace = true
+publish = true
+readme = "README.md"
+repository.workspace = true
+rust-version.workspace = true
+version.workspace = true
+
+[package.metadata.docs.rs]
+all-features = true
+
+
+[dependencies]
+anyhow.workspace = true
+glob = "0.3"
+time = { workspace = true, features = ["formatting"] }

crates/re_build_build_info/src/lib.rs

@@ -0,0 +1,92 @@
+//! This crate is to be used from `build.rs` build scripts.
+//!
+//! Use this crate together with the `re_build_info` crate.
+
+use anyhow::Context as _;
+
+use std::process::Command;
+
+// Situations to consider
+// ----------------------
+//
+// # Using the published crate
+//
+// The published crate carries its version around, which in turns gives us the git tag, which makes
+// the commit hash irrelevant.
+// We still need to compute _something_ so that we can actually build, but that value will be
+// ignored when the crate is built by the end user anyhow.
+//
+// # Working directly within the workspace
+//
+// When working within the workspace, we can simply try and call `git` and we're done.
+//
+// # Using an unpublished crate (e.g. `path = "..."` or `git = "..."` or `[patch.crates-io]`)
+//
+// In these cases we may or may not have access to the workspace (e.g. a `path = ...` import likely
+// will, while a crate patch won't).
+//
+// This is not an issue however, as we can simply try and see what we get.
+// If we manage to compute a commit hash, great, otherwise we still have the crate version to
+// fallback on.
+
+/// Call from the `build.rs` file of any crate you want to generate build info for.
+pub fn export_env_vars() {
+    // target triple
+    println!(
+        "cargo:rustc-env=RE_BUILD_TARGET_TRIPLE={}",
+        std::env::var("TARGET").unwrap()
+    );
+
+    let git_hash = git_hash().unwrap_or_default();
+    println!("cargo:rustc-env=RE_BUILD_GIT_HASH={git_hash}");
+
+    let git_branch = git_branch().unwrap_or_default();
+    println!("cargo:rustc-env=RE_BUILD_GIT_BRANCH={git_branch}");
+
+    let time_format =
+        time::format_description::parse("[year]-[month]-[day]T[hour]:[minute]:[second]Z").unwrap();
+    let date_time = time::OffsetDateTime::now_utc()
+        .format(&time_format)
+        .unwrap();
+    println!("cargo:rustc-env=RE_BUILD_DATETIME={date_time}");
+
+    // Make sure we re-run the build script if the branch or commit changes:
+    if let Ok(head_path) = git_path("HEAD") {
+        eprintln!("cargo:rerun-if-changed={head_path}"); // Track changes to branch
+        if let Ok(head) = std::fs::read_to_string(&head_path) {
+            if let Some(git_file) = head.strip_prefix("ref: ") {
+                if let Ok(path) = git_path(git_file) {
+                    eprintln!("cargo:rerun-if-changed={path}"); // Track changes to commit hash
+                }
+            }
+        }
+    }
+}
+
+fn run_command(cmd: &'static str, args: &[&str]) -> anyhow::Result<String> {
+    let output = Command::new(cmd)
+        .args(args)
+        .output()
+        .with_context(|| format!("running '{cmd}'"))?;
+    Ok(String::from_utf8(output.stdout)?.trim().to_owned())
+}
+
+fn git_hash() -> anyhow::Result<String> {
+    let git_hash = run_command("git", &["rev-parse", "HEAD"])?;
+    if git_hash.is_empty() {
+        anyhow::bail!("empty commit hash");
+    }
+    Ok(git_hash)
+}
+
+fn git_branch() -> anyhow::Result<String> {
+    run_command("git", &["symbolic-ref", "--short", "HEAD"])
+}
+
+/// From <https://git-scm.com/docs/git-rev-parse>:
+///
+/// Resolve `$GIT_DIR/<path>` and takes other path relocation variables such as `$GIT_OBJECT_DIRECTORY`, `$GIT_INDEX_FILE…​` into account.
+/// For example, if `$GIT_OBJECT_DIRECTORY` is set to /foo/bar then `git rev-parse --git-path objects/abc` returns `/foo/bar/abc`.
+fn git_path(path: &str) -> anyhow::Result<String> {
+    run_command("git", &["rev-parse", "--git-path", path])
+}

crates/re_build_info/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "re_build_info"
+authors.workspace = true
+description = "Information about the build. Use together with re_build_build_info"
+edition.workspace = true
+homepage.workspace = true
+include.workspace = true
+license.workspace = true
+publish = true
+readme = "README.md"
+repository.workspace = true
+rust-version.workspace = true
+version.workspace = true
+
+[package.metadata.docs.rs]
+all-features = true