Better context when erroring

pageserver/src/branches.rs

@@ -268,9 +268,22 @@ pub(crate) fn get_branches(
     // with timeline_id.
     let branches_dir = conf.branches_path(tenantid);
 
-    std::fs::read_dir(&branches_dir)?
+    std::fs::read_dir(&branches_dir)
+        .with_context(|| {
+            format!(
+                "Found no branches directory '{}' for tenant {}",
+                branches_dir.display(),
+                tenantid
+            )
+        })?
         .map(|dir_entry_res| {
-            let dir_entry = dir_entry_res?;
+            let dir_entry = dir_entry_res.with_context(|| {
+                format!(
+                    "Failed to list branches directory '{}' content for tenant {}",
+                    branches_dir.display(),
+                    tenantid
+                )
+            })?;
             BranchInfo::from_path(
                 dir_entry.path(),
                 conf,

pageserver/src/layered_repository/image_layer.rs

@@ -30,7 +30,7 @@ use crate::layered_repository::RELISH_SEG_SIZE;
 use crate::virtual_file::VirtualFile;
 use crate::PageServerConf;
 use crate::{ZTenantId, ZTimelineId};
-use anyhow::{anyhow, bail, ensure, Result};
+use anyhow::{anyhow, bail, ensure, Context, Result};
 use bytes::Bytes;
 use log::*;
 use serde::{Deserialize, Serialize};
@@ -386,8 +386,14 @@ impl ImageLayer {
         }
 
         let path = self.path();
-        let file = VirtualFile::open(&path)?;
-        let book = Book::new(file)?;
+        let file = VirtualFile::open(&path)
+            .with_context(|| format!("Failed to open virtual file '{}'", path.display()))?;
+        let book = Book::new(file).with_context(|| {
+            format!(
+                "Failed to open virtual file '{}' as a bookfile",
+                path.display()
+            )
+        })?;
 
         match &self.path_or_conf {
             PathOrConf::Conf(_) => {