test: fix sys.path patch to run local tests
diff --git a/test/run_all_tests.py b/test/run_all_tests.py
index c49dc53..e0797e7 100644
--- a/test/run_all_tests.py
+++ b/test/run_all_tests.py
@@ -15,7 +15,7 @@
import os
# inject local copy to avoid testing the installed version instead of the one in the repo
-sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import serial # noqa
print("Patching sys.path to test local version. Testing Version: {}".format(serial.VERSION))