git-sugpatch: Print error and exit on `Config::get` error

Add `exitcode` to exit with an appropriate code.

Add the `gseprintln` macro to wrap `eprintln!()`, prefixing the output
with "error: ".

1 files changed, 8 insertions, 0 deletions

diff --git a/src/error.rs b/src/error.rs
index c857bd2..bcca3e1 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -7,3 +7,11 @@ pub enum Error {
     #[error("Unable to parse regex")]
     Regex(#[from] regex::Error),
 }
+
+
+#[macro_export]
+macro_rules! gseprintln {
+    ($arg:expr) => ({
+        eprintln!("error: {}", $arg);
+    })
+}