Lock file does not exist / Empty filename error when getting cache ID on every cron run

I'm getting the following pairs of errors happen on every cron run:

Warning: file_get_contents(): Filename cannot be empty in composer_manager_sa_cache_cid() (line 128 of /sites/all/modules/composer_manager/composer_manager_sa/composer_manager_sa.module).

SensioLabs\Security\Exception\RuntimeException: Lock file does not exist. in SensioLabs\Security\SecurityChecker->check() (line 60 of /sites/all/vendor/sensiolabs/security-checker/SensioLabs/Security/SecurityChecker.php).

I had thought that it was related to this (https://www.drupal.org/node/2567885), but patches there do not solve the issue, and reading through that issue I realize that it seems like it is something else.

I'm on Pantheon.