build/bin/sage-system-python: Try python first

Author: Matthias Koeppe

build/bin/sage-system-python

@@ -20,7 +20,9 @@ fi
 #
 # See https://trac.sagemath.org/ticket/29090
 
-PYTHONS="python3 python3.8 python3.7 python2.7 python python3.6 python2"
+# Trac #29890: Our first choice is "python", not "python3". This is to avoid
+# a defect of sage_bootstrap on macOS regarding SSL URLs.
+PYTHONS="python python3 python3.8 python3.7 python2.7 python3.6 python2"
 for PY in $PYTHONS; do
     PYTHON="$(PATH="$SAGE_ORIG_PATH" command -v $PY)"
     if [[ -n "$PYTHON" ]]; then