diff --git a/apps/backend/src/api/hex_repo.gleam b/apps/backend/src/api/hex_repo.gleam
index 6bab680..2775816 100644
--- a/apps/backend/src/api/hex_repo.gleam
+++ b/apps/backend/src/api/hex_repo.gleam
@@ -4,6 +4,7 @@ import gleam/http
 import gleam/http/request
 import gleam/httpc
 import gleam/json
+import gleam/option
 import gleam/package_interface
 import gleam/result
 import simplifile
@@ -35,16 +36,28 @@ fn get_tarball(name: String, version: String) {
   |> result.map_error(error.FetchError)
 }
 
+fn read_interface(filepath: String) {
+  case simplifile.read(filepath) {
+    Ok(interface) -> Ok(option.Some(interface))
+    Error(_) -> Ok(option.None)
+  }
+}
+
 fn read_file(filepath: String) {
   filepath
   |> simplifile.read()
-  |> result.map_error(error.SimplifileError)
+  |> result.map_error(error.SimplifileError(_, filepath))
 }
 
-fn read_package_interface(blob: String) {
-  blob
-  |> json.decode(using: package_interface.decoder)
-  |> result.map_error(error.JsonError)
+fn read_package_interface(blob: option.Option(String)) {
+  case blob {
+    option.None -> Ok(option.None)
+    option.Some(blob) ->
+      blob
+      |> json.decode(using: package_interface.decoder)
+      |> result.map_error(error.JsonError)
+      |> result.map(option.Some)
+  }
 }
 
 fn read_gleam_toml(blob: String) {
@@ -58,7 +71,7 @@ fn extract_package_infos(name: String, version: String) {
   let req = get_tarball(name, version)
   use res <- result.try(req)
   let #(interface, toml) = extract_tar(res.body, name, slug)
-  use interface_blob <- result.try(read_file(interface))
+  use interface_blob <- result.try(read_interface(interface))
   use toml_blob <- result.try(read_file(toml))
   use interface <- result.try(read_package_interface(interface_blob))
   use toml <- result.map(read_gleam_toml(toml_blob))
diff --git a/apps/backend/src/api/signatures.gleam b/apps/backend/src/api/signatures.gleam
index 1558b41..00da2c1 100644
--- a/apps/backend/src/api/signatures.gleam
+++ b/apps/backend/src/api/signatures.gleam
@@ -49,7 +49,9 @@ fn get_package_release_ids(db: pgo.Connection, package: Package) {
   })
   response.rows
   |> list.first()
-  |> result.replace_error(error.UnknownError("No release"))
+  |> result.replace_error(error.UnknownError(
+    "No release found for " <> package.name <> "@" <> package.version,
+  ))
 }
 
 fn upsert_package_module(
@@ -74,7 +76,9 @@ fn upsert_package_module(
   })
   response.rows
   |> list.first()
-  |> result.replace_error(error.UnknownError("No module"))
+  |> result.replace_error(error.UnknownError(
+    "No module found for " <> module_name,
+  ))
 }
 
 fn upsert_type_definitions(
diff --git a/apps/backend/src/backend/index/error.gleam b/apps/backend/src/backend/index/error.gleam
index 3fead84..e860085 100644
--- a/apps/backend/src/backend/index/error.gleam
+++ b/apps/backend/src/backend/index/error.gleam
@@ -8,7 +8,7 @@ pub type Error {
   DatabaseError(pgo.QueryError)
   FetchError(dynamic.Dynamic)
   JsonError(json.DecodeError)
-  SimplifileError(simplifile.FileError)
+  SimplifileError(simplifile.FileError, String)
   UnknownError(String)
   TomlError(tom.ParseError)
 }
diff --git a/apps/backend/src/backend/log_error.gleam b/apps/backend/src/backend/log_error.gleam
index 3d57ad8..260ac73 100644
--- a/apps/backend/src/backend/log_error.gleam
+++ b/apps/backend/src/backend/log_error.gleam
@@ -49,8 +49,9 @@ pub fn log_error(error: error.Error) {
       wisp.log_warning("JSON error")
       log_decode_error(error)
     }
-    error.SimplifileError(error) -> {
+    error.SimplifileError(error, filepath) -> {
       wisp.log_warning("Simplifile error")
+      wisp.log_warning("  filepath: " <> filepath)
       log_simplifile(error)
     }
     error.UnknownError(error) -> {
diff --git a/apps/backend/src/gleam/generate/types.gleam b/apps/backend/src/gleam/generate/types.gleam
index 6bc3c58..7d3b3f4 100644
--- a/apps/backend/src/gleam/generate/types.gleam
+++ b/apps/backend/src/gleam/generate/types.gleam
@@ -151,7 +151,9 @@ fn find_package_release(
   response.rows
   |> keep_highest_release(requirement)
   |> option.map(fn(v) { pair.first(v) })
-  |> option.to_result(error.UnknownError("Release not found"))
+  |> option.to_result(error.UnknownError(
+    "Release " <> package <> " with conditions " <> requirement <> " not found",
+  ))
 }
 
 fn keep_highest_release(rows: List(#(Int, String)), requirement: String) {
@@ -193,7 +195,9 @@ fn find_type_signature(
   })
   response.rows
   |> list.first()
-  |> result.replace_error(error.UnknownError("No type defined"))
+  |> result.replace_error(error.UnknownError(
+    "No type found for " <> module <> "." <> name,
+  ))
 }
 
 fn extract_parameters_relation(
@@ -219,7 +223,7 @@ fn get_toml_requirement(gleam_toml: GleamToml, package: String) {
   |> result.try_recover(fn(_) {
     tom.get_string(gleam_toml, ["dependencies", package])
   })
-  |> result.replace_error(error.UnknownError("No dep found"))
+  |> result.replace_error(error.UnknownError("No dep found for " <> package))
 }
 
 fn is_prelude(package: String, module: String) {
diff --git a/apps/backend/src/tasks/hex.gleam b/apps/backend/src/tasks/hex.gleam
index bd8c29f..a2ec893 100644
--- a/apps/backend/src/tasks/hex.gleam
+++ b/apps/backend/src/tasks/hex.gleam
@@ -10,6 +10,7 @@ import birl.{type Time}
 import birl/duration
 import gleam/hexpm.{type Package}
 import gleam/list
+import gleam/option
 import gleam/order
 import gleam/otp/supervisor
 import gleam/pgo
@@ -130,7 +131,11 @@ fn insert_package_and_releases(
       retrier.retry(fn() {
         let infos = hex_repo.get_package_infos(package.name, r.version)
         use #(package, gleam_toml) <- result.try(infos)
-        signatures.extract_signatures(state.db, package, gleam_toml)
+        case package {
+          option.None -> Ok([])
+          option.Some(package) ->
+            signatures.extract_signatures(state.db, package, gleam_toml)
+        }
       })
     })
   })