Ruby interface for apngasm
If you are using rapngasm on Heroku you will need the rapngasm build pack to enable native compilation of the extension during bundling. You can find the buildpack here.
File a github issue
Submit an issue and put up a bounty on it here.
Genshin Souzou Kabushiki Kaisha
apngasm is copyright Max Stepin and is maintained by Max Stepin & Genshin Souzou K.K.