diff --git a/scripts/build_rln.sh b/scripts/build_rln.sh
index 44d4c0e11..cd2fa3827 100755
--- a/scripts/build_rln.sh
+++ b/scripts/build_rln.sh
@@ -33,11 +33,9 @@ if curl --silent --fail-with-body -L \
   -o "${tarball}";
 then
     echo "Downloaded ${tarball}"
-    tmpdir=$(mktemp -d)
-    tar -xzf "${tarball}" -C "$tmpdir"
-    mv "$tmpdir/release/librln.a" "${output_filename}"
-    rm -rf "${tarball}" "$tmpdir"
-    echo "finished building ${output_filename}"
+    tar -xzf "${tarball}"
+    mv "release/librln.a" "${output_filename}"
+    rm -rf "${tarball}" release
 else
     echo "Failed to download ${tarball}"
     # Build rln instead
diff --git a/waku/common/envvar_serialization/reader.nim b/waku/common/envvar_serialization/reader.nim
index 66869e3b4..a07a3a68f 100644
--- a/waku/common/envvar_serialization/reader.nim
+++ b/waku/common/envvar_serialization/reader.nim
@@ -96,7 +96,10 @@ proc readValue*[T](r: var EnvvarReader, value: var T) {.raises: [SerializationEr
           var reader = findFieldReader(fields[], fieldName, expectedFieldPos)
 
         if reader != nil:
-          reader(value, r)
+          try:
+            reader(value, r)
+          except IOError as e:
+            raise newException(SerializationError, "Envvar reader IO error: " & e.msg)
       discard r.key.pop()
   else:
     const typeName = typetraits.name(T)