diff --git a/spack/package.py b/spack/package.py
index cede9213..0b78d919 100644
--- a/spack/package.py
+++ b/spack/package.py
@@ -92,7 +92,12 @@ def setup_run_environment(self, env):
             self.spec.variants["precision"].value if self.spec.satisfies("@3.4.6:") else ("4", "d")
         )
         for suffix in precisions:
-            lib = find_libraries("libg2_" + suffix, root=self.prefix, shared=self.spec.satisfies("+shared"), recursive=True)
+            lib = find_libraries(
+                "libg2_" + suffix,
+                root=self.prefix,
+                shared=self.spec.satisfies("+shared"),
+                recursive=True,
+            )
             env.set("G2_LIB" + suffix, lib[0])
             env.set("G2_INC" + suffix, join_path(self.prefix, "include_" + suffix))