Conversation

しかたがないのでgit pushしてみるよ

$ heroku git:remote --remote add-gallery -a PRアプリ
$ git push add-gallery add-gallery:master
:
remote: Git submodules detected, installing:
remote: Submodule 'public/gallery' (https://source.joinmastodon.org/Gargron/gallery.git) registered for path 'public/gallery'
remote: Cloning into 'public/gallery'...
remote: Submodule path 'public/gallery': checked out '238031a29fba1e2bd4bd945c16c6abba566a9663'
:
$ heroku run 'ls -a public/gallery/'
. .gitignore package.json README.md yarn.lock
.. .gitlab-ci.yml public src

ふむん。これでも404かー。