cli: include commit id from build in version

This changes the version number reported by `jj version` from "0.7.0"
to something like
"0.7.0-24a512683bc921699575b6a953624b05c068d544a". The hash is added
if running in a jj repo or a git repo.

Cargo.lock

@@ -162,6 +162,38 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "89b2fd2a0dcf38d7971e2194b6b6eebab45ae01067456a7fd93d5547a61b70be"
 
+[[package]]
+name = "camino"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c530edf18f37068ac2d977409ed5cd50d53d73bc653c7647b48eb78976ac9ae2"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "cargo-platform"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cbdb825da8a5df079a43676dbe042702f1707b1109f713a01420fbb4cc71fa27"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "cargo_metadata"
+version = "0.15.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eee4243f1f26fc7a42710e7439c149e2b10b05472f88090acce52632f231a73a"
+dependencies = [
+ "camino",
+ "cargo-platform",
+ "semver",
+ "serde",
+ "serde_json",
+ "thiserror",
+]
+
 [[package]]
 name = "cast"
 version = "0.3.0"
@@ -791,6 +823,7 @@ version = "0.7.0"
 dependencies = [
  "assert_cmd",
  "assert_matches",
+ "cargo_metadata",
  "chrono",
  "clap 4.1.11",
  "clap_complete",
@@ -1568,6 +1601,15 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "semver"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.159"

Cargo.toml

@@ -29,6 +29,9 @@ path = "testing/fake-diff-editor.rs"
 [workspace]
 members = ["lib", "lib/testutils", "lib/gen-protos"]
 
+[build-dependencies]
+cargo_metadata = "0.15.4"
+
 [dependencies]
 chrono = { version = "0.4.24", default-features = false, features = ["std", "clock"] }
 clap = { version = "4.1.11", features = ["derive", "deprecated"] }

build.rs

@@ -0,0 +1,63 @@
+// Copyright 2023 The Jujutsu Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::process::Command;
+
+use cargo_metadata::MetadataCommand;
+
+fn main() -> std::io::Result<()> {
+    let path = std::env::var("CARGO_MANIFEST_DIR").unwrap();
+    let meta = MetadataCommand::new()
+        .manifest_path("./Cargo.toml")
+        .current_dir(&path)
+        .exec()
+        .unwrap();
+    let root = meta.root_package().unwrap();
+    let version = &root.version;
+
+    if let Some(git_hash) = get_git_hash() {
+        println!("cargo:rustc-env=JJ_VERSION={}-{}", version, git_hash);
+    } else {
+        println!("cargo:rustc-env=JJ_VERSION={}", version);
+    }
+
+    Ok(())
+}
+
+fn get_git_hash() -> Option<String> {
+    if let Ok(output) = Command::new("jj")
+        .args([
+            "--ignore-working-copy",
+            "log",
+            "--no-graph",
+            "-r=@-",
+            "-T=commit_id",
+        ])
+        .output()
+    {
+        if output.status.success() {
+            println!("cargo:rerun-if-changed=.jj/repo/op_heads/heads/");
+            return Some(String::from_utf8(output.stdout).unwrap());
+        }
+    }
+
+    if let Ok(output) = Command::new("git").args(["rev-parse", "HEAD"]).output() {
+        if output.status.success() {
+            println!("cargo:rerun-if-changed=.git/HEAD");
+            return Some(String::from_utf8(output.stdout).unwrap());
+        }
+    }
+
+    None
+}

src/cli_util.rs

@@ -1860,11 +1860,7 @@ pub fn short_operation_hash(operation_id: &OperationId) -> String {
 ///
 /// To get started, see the tutorial at https://github.com/martinvonz/jj/blob/main/docs/tutorial.md.
 #[derive(clap::Parser, Clone, Debug)]
-#[command(
+#[command(name = "jj", author = "Martin von Zweigbergk <martinvonz@google.com>")]
-    name = "jj",
-    author = "Martin von Zweigbergk <martinvonz@google.com>",
-    version
-)]
 pub struct Args {
     #[command(flatten)]
     pub global_args: GlobalArgs,

src/commands/mod.rs

@@ -3445,7 +3445,9 @@ fn cmd_sparse(ui: &mut Ui, command: &CommandHelper, args: &SparseArgs) -> Result
 
 pub fn default_app() -> Command {
     let app: Command = Commands::augment_subcommands(Args::command());
-    app.arg_required_else_help(true).subcommand_required(true)
+    app.arg_required_else_help(true)
+        .subcommand_required(true)
+        .version(env!("JJ_VERSION"))
 }
 
 pub fn run_command(

tests/test_global_opts.rs

@@ -55,9 +55,12 @@ fn test_no_subcommand() {
     insta::assert_snapshot!(stderr.lines().next().unwrap(), @"error: 'jj' requires a subcommand but one was not provided");
 
     let stdout = test_env.jj_cmd_success(test_env.env_root(), &["--version"]);
-    insta::assert_snapshot!(stdout.replace(|c: char| c.is_ascii_digit(), "?"), @r###"
+    let sanitized = stdout.replace(|c: char| c.is_ascii_hexdigit(), "?");
-    jj ?.?.?
+    assert!(
-    "###);
+        sanitized == "jj ?.?.?\n"
+            || sanitized == "jj ?.?.?-????????????????????????????????????????\n",
+        "{sanitized}"
+    );
 
     let stdout = test_env.jj_cmd_success(test_env.env_root(), &["--help"]);
     insta::assert_snapshot!(stdout.lines().next().unwrap(), @"Jujutsu (An experimental VCS)");