This PR is trying to fix issue #36956.
The stage name is case-insensitive by design, so we should use
`strings.EqualFold()` as the comparison method to eliminate the
case sensitive noise.
Also we need to return a pre-defined error code order to avoid below
message like:
"FIXME: Got an API for which error does not match any expected type!!!:
failed to reach build target dev in Dockerfile"
Signed-off-by: Dennis Chen <dennis.chen@arm.com>
This is a work base to introduce more features like build time
dockerfile optimisations, dependency analysis and parallel build, as
well as a first step to go from a dispatch-inline process to a
frontend+backend process.
Signed-off-by: Simon Ferquel <simon.ferquel@docker.com>
