Builds are available here: https://github.com/samcv/rakudo-appimage/tree/gh-pages
They are built by Travis CI and commited to the gh-pages branch.
If cloning please use:
git clone --single-branch https://github.com/samcv/rakudo-appimage.git
or
git clone --single-branch git@github.com:samcv/rakudo-appimage.git
Otherwise it will clone all the branches, which contain the full history of all AppImage builds, several hundred megabytes.