diff --git a/Makefile b/Makefile
index 6024268..889cfaf 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,7 @@ ${SO}: bp.o params.o drop.o pysib.cpp ${DEP}
 test: ${DOCTEST}
 
 env:
+	ls $(dirname ${PYTHON})
 	@which ${PYTHON}
 	@which ${PYTHON_CONFIG}