ci: add missing CFLAGS variable to print_environment

Author: jonasnick

ci/cirrus.sh

@@ -19,11 +19,14 @@ print_environment() {
     do
         eval 'printf "%s %s " "$i=\"${'"$i"'}\""'
     done
-    # In contrast to the previous variables, CC, AR and NM may be unset. Print
-    # them if they are set (even if set to the empty string).
+    # In contrast to the previous variables, CC, CFLAGS, AR and NM may be unset.
+    # Print them if they are set (even if set to the empty string).
     if [ -n "${CC+x}" ]; then
         echo -n "CC=\"${CC}\" "
     fi
+    if [ -n "${CFLAGS+x}" ]; then
+        echo -n "CFLAGS=\"${CFLAGS}\" "
+    fi
     if [ -n "${AR+x}" ]; then
         echo -n "AR=\"${AR}\" "
     fi