Switch to git-testament rather than old build.rs

Rather than the previous not-very-informative version string
which was generated by build.rs and then not updated unless
build.rs was touched, use the new `git-testament` crate which
does a more complete job at compile time via a proc-macro.

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

Author: kinnison

Cargo.lock

@@ -47,6 +47,8 @@ wait-timeout = "0.1.5"
 walkdir = "2.0"
 xz2 = "0.1.3"
 openssl = { version = '0.10.15', optional = true }
+git-testament = "0.1.0"
+lazy_static = "1"
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3", features = ["combaseapi", "errhandlingapi", "fileapi", "handleapi", "ioapiset", "jobapi", "jobapi2", "minwindef", "processthreadsapi", "psapi", "shlobj", "shtypes", "synchapi", "sysinfoapi", "tlhelp32", "userenv", "winbase", "winerror", "winioctl", "winnt", "winuser"] }

Cargo.toml

@@ -1,57 +1,6 @@
 use std::env;
-use std::error::Error;
-use std::fs::File;
-use std::io::Write;
-use std::path::PathBuf;
-use std::process::Command;
-
-struct Ignore;
-
-impl<E> From<E> for Ignore
-where
-    E: Error,
-{
-    fn from(_: E) -> Ignore {
-        Ignore
-    }
-}
 
 fn main() {
     let target = env::var("TARGET").unwrap();
     println!("cargo:rustc-env=TARGET={}", target);
-
-    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
-    File::create(out_dir.join("commit-info.txt"))
-        .unwrap()
-        .write_all(commit_info().as_bytes())
-        .unwrap();
-
-    println!("cargo:rerun-if-changed=build.rs");
-}
-
-// Try to get hash and date of the last commit on a best effort basis. If anything goes wrong
-// (git not installed or if this is not a git repository) just return an empty string.
-fn commit_info() -> String {
-    match (commit_hash(), commit_date()) {
-        (Ok(hash), Ok(date)) => format!(" ({} {})", hash.trim_end(), date),
-        _ => String::new(),
-    }
-}
-
-fn commit_hash() -> Result<String, Ignore> {
-    Ok(String::from_utf8(
-        Command::new("git")
-            .args(&["rev-parse", "--short=9", "HEAD"])
-            .output()?
-            .stdout,
-    )?)
-}
-
-fn commit_date() -> Result<String, Ignore> {
-    Ok(String::from_utf8(
-        Command::new("git")
-            .args(&["log", "-1", "--date=short", "--pretty=format:%cd"])
-            .output()?
-            .stdout,
-    )?)
 }

build.rs

@@ -3,6 +3,8 @@
 use crate::errors::*;
 use crate::self_update;
 use crate::term2;
+use git_testament::{git_testament, render_testament};
+use lazy_static::lazy_static;
 use rustup::utils::notify::NotificationLevel;
 use rustup::utils::utils;
 use rustup::{Cfg, Notification, Toolchain, UpdateStatus};
@@ -402,11 +404,13 @@ pub fn list_overrides(cfg: &Cfg) -> Result<()> {
     Ok(())
 }
 
+git_testament!(TESTAMENT);
+
 pub fn version() -> &'static str {
-    concat!(
-        env!("CARGO_PKG_VERSION"),
-        include_str!(concat!(env!("OUT_DIR"), "/commit-info.txt"))
-    )
+    lazy_static! {
+        static ref RENDERED: String = render_testament!(TESTAMENT);
+    }
+    &RENDERED
 }
 
 pub fn report_error(e: &Error) {