diff --git a/helper/start-bash-session.sh b/helper/start-bash-session.sh
new file mode 100644
index 0000000..f4fa67d
--- /dev/null
+++ b/helper/start-bash-session.sh
@@ -0,0 +1,12 @@
+# Start an interactive bash session in the current bash environment.
+# This is helpful for debugging bash scripts like pkg update scripts,
+# by adding `source <path-to>/start-bash-session.sh` at the location to
+# be inspected.
+
+
+# BASH_ENVIRONMENT contains definitions of read-only variables like 'BASHOPTS' that
+# cause warnings on evaluation. Suppress these warnings while sourcing.
+#
+# shellcheck disable=SC2016
+BASH_ENVIRONMENT=<(declare -p; declare -pf) \
+  bash --rcfile <(echo 'source $BASH_ENVIRONMENT 2>/dev/null')