[BUG] actionable error message after buildkit endpoint checks are exhausted

[toddysm]

Version of copa

copa version 0.10.0

Expected Behavior

Copa runs without containerd snapshotter.

Actual Behavior

I am running Copa on a MacOS Sequoia 15.3.2 with Docker Desktop Version 4.39.0 (184744) installed. Trying to run Copa with the default configuration of Docker Desktop results in the following error:

$ copa patch -i alpine:3.20.0 -t 3.20.0-patched                                                  
Error: could not use docker driver: failed to solve: requested experimental feature mergeop  has been disabled on the build server: only enabled with containerd image store backend
requested experimental feature diffop  has been disabled on the build server: only enabled with containerd image store backend
missing required buildkit functionality
could not use buildx driver: listing workers for Build: failed to list workers: Unavailable: connection error: desc = "transport: Error while dialing: read /Users/toddysm/.docker/buildx/instances: is a directory"
could not use buildkitd driver: %!w(<nil>)

Configuring Docker Desktop with the containerd snapshotter (https://docs.docker.com/engine/storage/containerd/) fixes the issue. Reverting back the configuration reproduces the issue.

Steps To Reproduce

No response

Are you willing to submit PRs to contribute to this bug fix?

• Yes, I am willing to implement it.

[sozercan]

@toddysm this works as intended, as copa requires a buildkit instance to work. options are documented in https://project-copacetic.github.io/copacetic/website/custom-address

we should make the error messages actionable and user friendly so next steps are clear.

[sozercan]

@amanycodes this is a good one to pick up if you are interested

[blazethunderstorm]

@sozercan i have made pr for this issue