drop thiserror

src/lib.rs

@@ -1,16 +1,30 @@
 use std::borrow::Cow;
 use std::env::var;
+use std::error::Error;
+use std::fmt::Display;
 use std::fs::read_to_string;
-use thiserror::Error;
 
-#[derive(Debug, Error)]
+#[derive(Debug)]
 pub enum SecretError {
-    #[error("failed to load token from {path}: {error:#}")]
     Load { path: String, error: std::io::Error },
-    #[error("environment variable {0} referenced but not set")]
     MissingEnvVar(String),
 }
 
+impl Display for SecretError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            SecretError::Load { path, error } => {
+                write!(f, "failed to load token from {path}: {error:#}")
+            }
+            SecretError::MissingEnvVar(var) => {
+                write!(f, "environment variable {var} referenced but not set")
+            }
+        }
+    }
+}
+
+impl Error for SecretError {}
+
 /// Load a secret from the provided path
 ///
 /// If the provided path includes the `$CREDENTIALS_DIRECTORY` placeholder, it will be replaced with the