Fixing ‘Bootsnap doesn’t have permission to write cache entries’ errors


Version 1.4.2 of Bootsnap has a bug that causes the cache file to be created with permissions set to 600. This means the file cannot be read by other processes (web or worker) since they are in different groups, and breaks the build process.


There are two ways to resolve this issue (in order of preference):

  • Upgrade Bootsnap to version 1.4.3 (in which the bug is fixed) or above (you can also downgrade to v1.4.1).
  • Add a deploy hook at the after_symlink hook point that creates the creates the cache folder with the correct permissions (see below).

In either case we strongly recommend you redeploy your application rather than manually CHMOD-ing any files or directories (see below).

Example of a deploy hook

The hook point for this deploy hook is after_symlink

Add a deploy hook to your deploy_hooks.yml with the following command:

mkdir -p $RAILS_STACK_PATH/tmp/cache/bootsnap-compile-cache

This will create the directory with the correct permissions and the build should be able to complete.


If you just CHMOD the directory that Bootsnap creates, either manually or via a hook, the permissions will change again as soon as new files are created by Bootsnap.