cancel update script execution if something goes wrong

update_all.sh

 #!/bin/sh
 
+set -eu
+
 main_repo=$(pwd)
 
 git_save() {
         git stash push --include-untracked
         return 0
     else
+        set +e
         return 1
     fi
 }
 cd $main_repo/battle_engine
 git_save
 result=$?
+set -e
 git checkout master
 git pull
 git_restore $result
 cd $main_repo/g3headers
 git_save
 result=$?
+set -e
 git checkout master
 git pull
 git_restore $result
 cd $main_repo/sots-private
 git_save
 result=$?
+set -e
 git checkout master
 git pull
 git_restore $result