/usr/share/sagemath/bin/sage-upgrade is in sagemath-common 7.4-9.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 | #!/usr/bin/env bash
# This script must be run from $SAGE_ROOT and without having sourced
# sage-env.
set -e
# Update sources
local/bin/sage-update-src "$@"
# Run top-level make
exec make
|