feat: make errors have a source error

When errors have a source, i.e., an underlying error, it results in
better error messages to the user.

Also, refactor the way the source chain is printed, to code that is
clearer to me.

I will need this to for loading document metadata from an external
YAML file.

Sponsored-by: author

1 files changed, 5 insertions, 8 deletions

diff --git a/src/bin/subplot.rs b/src/bin/subplot.rs
index e9cb00a..5e802b4 100644
--- a/src/bin/subplot.rs
+++ b/src/bin/subplot.rs
@@ -504,13 +504,6 @@ fn load_linted_doc(
     Ok(doc)
 }
 
-fn print_source_errors(e: Option<&dyn std::error::Error>) {
-    if let Some(e) = e {
-        error!("{}", e);
-        print_source_errors(e.source());
-    }
-}
-
 fn real_main() {
     info!("Starting Subplot");
     let argparser = Toplevel::command();
@@ -525,7 +518,11 @@ fn real_main() {
         }
         Err(e) => {
             error!("{}", e);
-            print_source_errors(e.source());
+            let mut e = e.source();
+            while let Some(source) = e {
+                error!("caused by: {}", source);
+                e = source.source();
+            }
             process::exit(1);
         }
     }