use const format for version string

crates/pacdef_core/Cargo.toml

@@ -13,6 +13,7 @@ categories = ["command-line-utilities"]
 alpm = "2.2"
 anyhow = {workspace = true}
 clap = "4.1"
+const_format = { version = "0.2", default-features = false }
 path-absolutize = "3.0"
 regex = "1.7"
 termios = "0.3"
@@ -23,3 +24,4 @@ serde_derive = "1.0"
 serde = "1.0"
 
 pacdef_macros = {path = "../pacdef_macros", version = "0.1"}
+

crates/pacdef_core/src/core.rs

@@ -5,6 +5,7 @@ use std::path::Path;
 
 use anyhow::{anyhow, bail, ensure, Context, Result};
 use clap::ArgMatches;
+use const_format::formatcp;
 
 use crate::action::*;
 use crate::args;
@@ -338,11 +339,12 @@ fn show_error(error: &anyhow::Error, backend: &dyn Backend) {
 }
 
 pub const fn get_version_string() -> &'static str {
-    concat!(
-        "pacdef, version: ",
-        env!("CARGO_PKG_VERSION"),
-        " (",
-        env!("GIT_HASH"),
-        ")",
-    )
+    const VERSION: &str = concat!("pacdef, version: ", env!("CARGO_PKG_VERSION"));
+    const HASH: &str = env!("GIT_HASH");
+
+    if HASH.is_empty() {
+        VERSION
+    } else {
+        formatcp!("{VERSION} ({HASH})")
+    }
 }