[eleventy-plugin-compress] Errors on files created via addPassthroughCopy, invalid output

[justinfagnani]

I'm getting errors using eleventy-plugin-compress on a fairly simple config that uses addPassthroughCopy() for some CSS and images:

 11:42:06 AM -> Icons: Error: ENOENT: no such file or directory, open '/Users/justin/Projects/justinfagnani.com/packages/content/site/css/prism-okaidia.css'
Error: ENOENT: no such file or directory, open '/Users/justin/Projects/justinfagnani.com/packages/content/site/css/prism-okaidia.css' 💥
 11:42:06 AM -> Icons: Start to compress "site/css/prism-okaidia.css" file 🆙
 11:42:06 AM -> Icons: Error: ENOENT: no such file or directory, open '/Users/justin/Projects/justinfagnani.com/packages/content/site/css/styles.css'
Error: ENOENT: no such file or directory, open '/Users/justin/Projects/justinfagnani.com/packages/content/site/css/styles.css' 💥
 11:42:06 AM -> Icons: Start to compress "site/css/styles.css" file 🆙

An addition to the errors, the plugin still writes a .br file, but it's empty, causing the files to fail to load in the browser.