Ensure build script doesn't fail outside git

Author: dalegaard

tool/build.rs

@@ -1,21 +1,22 @@
 use anyhow::Result;
 
+fn describe_git() -> Result<String> {
+    let dir = std::env::current_dir()?;
+    let repo = git2::Repository::discover(dir)?;
+    let mut desc_opts = git2::DescribeOptions::new();
+    desc_opts.describe_tags();
+    let desc = repo.describe(&desc_opts)?;
+    let mut fmt_opts = git2::DescribeFormatOptions::new();
+    fmt_opts.dirty_suffix("-dirty");
+    Ok(desc.format(Some(&fmt_opts))?)
+}
+
 fn main() -> Result<()> {
     println!("cargo:rerun-if-env-changed=TOOL_VERSION");
 
-    let version = match dbg!(std::env::var("TOOL_VERSION")) {
-        Ok(value) => value,
-        _ => {
-            let dir = std::env::current_dir()?;
-            let repo = git2::Repository::discover(dir)?;
-            let mut desc_opts = git2::DescribeOptions::new();
-            desc_opts.describe_tags();
-            let desc = repo.describe(&desc_opts)?;
-            let mut fmt_opts = git2::DescribeFormatOptions::new();
-            fmt_opts.dirty_suffix("-dirty");
-            desc.format(Some(&fmt_opts))?
-        }
-    };
+    let version = std::env::var("TOOL_VERSION")
+        .or_else(|_| describe_git())
+        .unwrap_or_else(|_| "unknown".into());
 
     println!("cargo:rustc-env=TOOL_VERSION={version}");