It only mounts But if you use `Host

[whole ferry]

I see. If the Host.Directory will be copy. Is there any other way to mount a directory from host into the runner without copy it?

my 2nd thought is that because the runner got started before, so we actually need to copy the host directory into the runner right?

[fallow parcel]

You have to copy from the client host no matter what, in order to have caching and also because the runner might be on a different machine

[whole ferry]

I see. That make sense. So actually we need to decouple from CI runner and dagger engine right?

1 more question. For example, I need to run CI for 2 different Pull Request. Both of these 2 PR will be run in the same dagger engine (presumably because AFAIK, dagger does not have self-provision engine yet)
will these 2 PR invalidate cache of each other because they have different source code?
another thing is how do we remove the cache of each PR after the CI finished?

[hard lion]

Hi,
Currently Dagger autoprovisions itself when a Docker daemon is present. So, if, for example, just run go run main.go in Github Action (which include the Go SDK), it will autoprovision itself (if not already present). Regarding the cache invalidation, it really depends on the implementation you intend to have: in the given example configuration (above), each PR will have their infra, thus install their own engine with the corresponding cache. We used to have primitives to export / import cache, but this is currently under discussion, as it isn't as straightforward

Do you have any needs ? What would be your ideal use-case ? 👼

[whole ferry]

I see. My use case is that i want to reuse cache between multiple runs for the same PR

The compiler generate kind of intermediate build artifact which can be reuse again for incremental compile. So lets say my PR CI run multiple time, then it shouldnt need to do full compile again after each build. But different PR must not use intermediate artifsct of each other

Do I need to have a dedicated dagger engine for each PR? And can the engine be reused for multiple run of a PR?