From 80e428ee60b51174593cd61ca3f85c37047dfbb0 Mon Sep 17 00:00:00 2001
From: Brandon Thomas <echelon@gmail.com>
Date: Wed, 25 Mar 2026 17:17:25 -0400
Subject: [PATCH] errors

---
 crates/lib/pager/src/client/pager_builder.rs  |  4 ++--
 crates/lib/pager/src/error/mod.rs             |  1 +
 .../pager/src/error/pager_builder_error.rs    | 19 +++++++++++++++++++
 crates/lib/pager/src/error/pager_error.rs     | 13 ++++++++++++-
 .../lib/pager/src/error/pager_system_error.rs |  6 +-----
 5 files changed, 35 insertions(+), 8 deletions(-)
 create mode 100644 crates/lib/pager/src/error/pager_builder_error.rs

diff --git a/crates/lib/pager/src/client/pager_builder.rs b/crates/lib/pager/src/client/pager_builder.rs
index a83e96cc83..c45f9aefa3 100644
--- a/crates/lib/pager/src/client/pager_builder.rs
+++ b/crates/lib/pager/src/client/pager_builder.rs
@@ -4,8 +4,8 @@ use rootly_client::creds::rootly_api_key::RootlyApiKey;
 
 use crate::client::pager::Pager;
 use crate::client::pager_client::{PagerClient, PagerClientConfig};
+use crate::error::pager_builder_error::PagerBuilderError;
 use crate::error::pager_error::PagerError;
-use crate::error::pager_system_error::PagerSystemError;
 use crate::worker::pager_worker_message_queue::{new_shared_queue, new_shared_queue_with_capacity, PagerWorkerMessageQueue};
 use crate::worker::pager_worker::PagerWorker;
 
@@ -104,7 +104,7 @@ impl PagerBuilder {
 
   fn make_client(&self) -> Result<PagerClient, PagerError> {
     let client_config = self.client_config.clone()
-      .ok_or(PagerSystemError::NoBackendConfigured)?;
+      .ok_or(PagerBuilderError::NoBackendConfigured)?;
 
     Ok(PagerClient::new(client_config, self.application_name.clone(), self.environment.clone()))
   }
diff --git a/crates/lib/pager/src/error/mod.rs b/crates/lib/pager/src/error/mod.rs
index 0bdf17fee4..f7371b8fb6 100644
--- a/crates/lib/pager/src/error/mod.rs
+++ b/crates/lib/pager/src/error/mod.rs
@@ -1,3 +1,4 @@
+pub mod pager_builder_error;
 pub mod pager_error;
 pub mod pager_service_error;
 pub mod pager_system_error;
diff --git a/crates/lib/pager/src/error/pager_builder_error.rs b/crates/lib/pager/src/error/pager_builder_error.rs
new file mode 100644
index 0000000000..140c1661e6
--- /dev/null
+++ b/crates/lib/pager/src/error/pager_builder_error.rs
@@ -0,0 +1,19 @@
+use std::error::Error;
+use std::fmt::{Display, Formatter};
+
+/// Errors from building/configuring a Pager instance.
+#[derive(Debug)]
+pub enum PagerBuilderError {
+  /// The pager was not configured with a backend.
+  NoBackendConfigured,
+}
+
+impl Error for PagerBuilderError {}
+
+impl Display for PagerBuilderError {
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::NoBackendConfigured => write!(f, "No pager backend configured. Call .rootly() or .client_config() on PagerBuilder."),
+    }
+  }
+}
diff --git a/crates/lib/pager/src/error/pager_error.rs b/crates/lib/pager/src/error/pager_error.rs
index debbc8d09c..24e1c7d8e2 100644
--- a/crates/lib/pager/src/error/pager_error.rs
+++ b/crates/lib/pager/src/error/pager_error.rs
@@ -1,16 +1,20 @@
 use std::error::Error;
 use std::fmt::{Display, Formatter};
 
+use crate::error::pager_builder_error::PagerBuilderError;
 use crate::error::pager_service_error::PagerServiceError;
 use crate::error::pager_system_error::PagerSystemError;
 
 /// Top-level error type for the pager library.
 #[derive(Debug)]
 pub enum PagerError {
+  /// An error during Pager construction/configuration.
+  Builder(PagerBuilderError),
+
   /// A third-party paging service (Rootly, etc.) returned an error.
   Service(PagerServiceError),
 
-  /// Our own pager system broke (configuration, mutex, queue, etc.).
+  /// Our own pager system broke (mutex, queue, etc.).
   System(PagerSystemError),
 }
 
@@ -19,12 +23,19 @@ impl Error for PagerError {}
 impl Display for PagerError {
   fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
     match self {
+      Self::Builder(err) => write!(f, "PagerBuilderError: {}", err),
       Self::Service(err) => write!(f, "PagerServiceError: {}", err),
       Self::System(err) => write!(f, "PagerSystemError: {}", err),
     }
   }
 }
 
+impl From<PagerBuilderError> for PagerError {
+  fn from(err: PagerBuilderError) -> Self {
+    Self::Builder(err)
+  }
+}
+
 impl From<PagerServiceError> for PagerError {
   fn from(err: PagerServiceError) -> Self {
     Self::Service(err)
diff --git a/crates/lib/pager/src/error/pager_system_error.rs b/crates/lib/pager/src/error/pager_system_error.rs
index 85e5486fd4..33b6b92e99 100644
--- a/crates/lib/pager/src/error/pager_system_error.rs
+++ b/crates/lib/pager/src/error/pager_system_error.rs
@@ -1,12 +1,9 @@
 use std::error::Error;
 use std::fmt::{Display, Formatter};
 
-/// Errors from our own pager system (configuration, concurrency, etc.).
+/// Errors from our own pager system at runtime (concurrency, queue, etc.).
 #[derive(Debug)]
 pub enum PagerSystemError {
-  /// The pager was not configured with a backend.
-  NoBackendConfigured,
-
   /// The message queue was not configured. Use `build_with_worker()` to enable queuing.
   QueueNotConfigured,
 
@@ -19,7 +16,6 @@ impl Error for PagerSystemError {}
 impl Display for PagerSystemError {
   fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
     match self {
-      Self::NoBackendConfigured => write!(f, "No pager backend configured. Call .rootly() or .client_config() on PagerBuilder."),
       Self::QueueNotConfigured => write!(f, "Pager message queue not configured. Use build_with_worker() to enable queuing."),
       Self::MutexPoisoned(msg) => write!(f, "Pager mutex poisoned: {}", msg),
     }