Mounted directory with withMountedDirectory is not updated on host

[miroljub1995]

I'm having local dagger v0.9.10 (registry.dagger.io/engine) darwin/arm64 and having mounted directory using withMountedDirectory and expected that changes to that directory are reflected in host, but no changes are made to host directory.
If that's by design, then what's the difference between withMountedDirectory and withDirectory?

[marcosnils]

hey there! WithMountedDirectory works the same way as the RUN --mount instruction that you see in Dockerfiles.

It's not bind mounting the files in your machine to the build, what it does is mounting the files from your build context into your pipeline so your resulting container doesn't contain those files in the layered filesystem. If you want the files that you change in your pipeline in your host, you need to use the Export function. There's more info about that here: https://docs.dagger.io/421437/work-with-host-filesystem/#export-a-directory-from-a-container-to-the-host

[miroljub1995]

I see, thanks for the quick reply.
The only problem I see, also where we needed mounting, is getting test results for later use. The problem is that export to host will not be executed if test fails.

[marcosnils]

re: container exit, we have a cookbook for those cases here: https://docs.dagger.io/cookbook/#continue-using-container-after-command-execution-fails