Any update for this ? Some dependencies (like php-ffmpeg) seems to not be compatible with roots/acorn v2 :

Fatal error: Declaration of Illuminate\Container\Container::has($id) must be compatible with Psr\Container\ContainerInterface::has(string $id): bool in /app/vendor/illuminate/container/Container.php on line 194

Upgrading to roots/acorn v3 seems to resolve this issue, but we can't show any view for the moment...

Upgrading to roots/acorn v3 seems to resolve this issue, but we can't show any view for the moment..

What update are you looking for? This PR demonstrates how to correctly upgrade to Acorn v3 and doesn't contain the error that you're describing. It's not going to be merged until Acorn v3 has a stable release.

After upgrading, I got this error too : Target class [sage.view] does not exist.

After upgrading, I got this error too : Target class [sage.view] does not exist.

Double check your ThemeServiceProvider making sure it extends SageServiceProvider and has parent:: calls to register() and boot() if they are present. You can reference my latest commit.