1  use std::env;
 2  use std::process::Command;
 3  
 4  fn main() -> Result<(), Box<dyn std::error::Error>> {
 5      // Set a build-time `GIT_HEAD` env var which includes the commit id;
 6      // such that we can tell which code is running.
 7      let hash = env::var("GIT_HEAD").unwrap_or_else(|_| {
 8          Command::new("git")
 9              .arg("rev-parse")
10              .arg("--short")
11              .arg("HEAD")
12              .output()
13              .ok()
14              .and_then(|output| {
15                  if output.status.success() {
16                      String::from_utf8(output.stdout).ok()
17                  } else {
18                      None
19                  }
20              })
21              .unwrap_or("unknown".into())
22      });
23  
24      let version = if let Ok(version) = env::var("RADICLE_VERSION") {
25          version
26      } else {
27          "pre-release".to_owned()
28      };
29  
30      // Set a build-time `SOURCE_DATE_EPOCH` env var which includes the commit time.
31      let commit_time = env::var("SOURCE_DATE_EPOCH").unwrap_or_else(|_| {
32          Command::new("git")
33              .arg("log")
34              .arg("-1")
35              .arg("--pretty=%ct")
36              .arg("HEAD")
37              .output()
38              .ok()
39              .and_then(|output| {
40                  if output.status.success() {
41                      String::from_utf8(output.stdout).ok()
42                  } else {
43                      None
44                  }
45              })
46              .unwrap_or(0.to_string())
47      });
48  
49      println!("cargo::rustc-env=RADICLE_VERSION={version}");
50      println!("cargo::rustc-env=SOURCE_DATE_EPOCH={commit_time}");
51      println!("cargo::rustc-env=GIT_HEAD={hash}");
52  
53      Ok(())
54  }