Show backtrace on error if RUST_BACKTRACE=1 is in the environment (#21)

Author: quodlibetor

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 * Remove last dependency on external git binary, using libgit2 for all git interactions
+* Show backtraces on error if RUST_BACKTRACE=1 is in the environment
 
 # Version 0.2.0
 

Cargo.lock

@@ -16,7 +16,7 @@ license = false
 eula = false
 
 [dependencies]
-anyhow = "1.0.79"
+anyhow = { version = "1.0.79", features = ["backtrace"] }
 clap = { version = "4.5.1", features = ["derive", "env", "wrap_help"] }
 console = "0.15.8"
 dialoguer = "0.11.0"

Cargo.toml

@@ -72,7 +72,11 @@ fn main() {
         // An empty message means don't display any error message
         let msg = e.to_string();
         if !msg.is_empty() {
-            println!("Error: {:#}", e);
+            if env::var("RUST_BACKTRACE").as_deref() == Ok("1") {
+                println!("Error: {:?}", e);
+            } else {
+                println!("Error: {:#}", e);
+            }
         }
         std::process::exit(1);
     }

src/main.rs

@@ -116,6 +116,7 @@ new
 #[test]
 fn test_no_commit_in_range() {
     let td = assert_fs::TempDir::new().unwrap();
+    eprintln!("tempdir: {:?}", td.path());
     git_init(&td);
 
     git_commits(&["a", "b", "c", "d"], &td);
@@ -145,9 +146,11 @@ fn test_no_commit_in_range() {
 
     let assertion = fixup(&td).args(&["-P", "b"]).assert().failure();
     let out = string(assertion.get_output().stdout.clone());
+    let expected = "No commit contains the pattern";
     assert!(
-        out.contains("No commit contains the pattern"),
-        "actual: {}",
+        out.contains(expected),
+        "expected: {}\nactual: {}",
+        expected,
         out
     );