diff --git a/plugins/python-build/bin/python-build b/plugins/python-build/bin/python-build
index 044defde..a30f6697 100755
--- a/plugins/python-build/bin/python-build
+++ b/plugins/python-build/bin/python-build
@@ -19,7 +19,10 @@ PYTHON_BUILD_VERSION="20180424"
 OLDIFS="$IFS"
 
 set -E
-[ -n "$PYENV_DEBUG" ] && set -x
+[ -n "$PYENV_DEBUG" ] && {
+  export PS4='+(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
+  set -x
+}
 
 exec 3<&2 # preserve original stderr at fd 3