finch build fails on '#syntax' directive in Dockerfile

[vsiravar]

Describe the bug
Briefly describe the problem you are having.
finch build fails when there is a syntax directive in the Dockerfile.

Steps to reproduce
A clear, step-by-step set of instructions to reproduce the bug.

cat Dockerfile
# syntax=docker/dockerfile:1
FROM public.ecr.aws/docker/library/golang:1.18 AS builder
WORKDIR /build
COPY . .

ARG TARGET_OS
ARG TARGET_ARCH
RUN go env -w GO111MODULE=off
RUN CGO_ENABLED=0 GOOS=${TARGET_OS} GOARCH=${TARGET_ARCH} go build -a -installsuffix cgo -ldflags '-extldflags "-static"' -o hello .

FROM scratch
EXPOSE 8080
COPY --from=builder /build/hello /app/
WORKDIR /app
ENTRYPOINT ["./hello"]

finch build -f Dockerfile -t test:syntax . 
[+] Building 2.9s (4/4) FINISHED                                                      
 => [internal] load .dockerignore                                                0.0s
 => => transferring context: 2B                                                  0.0s
 => [internal] load build definition from Dockerfile                             0.0s
 => => transferring dockerfile: 445B                                             0.0s
 => resolve image config for docker.io/docker/dockerfile:1                       1.6s
 => docker-image://docker.io/docker/dockerfile:1@sha256:9ba7531bd80fb0a85863272  1.1s
 => => resolve docker.io/docker/dockerfile:1@sha256:9ba7531bd80fb0a858632727cf7  0.0s
 => => sha256:0f354329a20e6c1067c0e51abd3b1721483fafbbe0c333710 8.39MB / 9.21MB  1.3s
 => => extracting sha256:0f354329a20e6c1067c0e51abd3b1721483fafbbe0c33371005980  0.1s
Dockerfile:1
--------------------
   1 | >>> # syntax=docker/dockerfile:1
   2 |     FROM public.ecr.aws/docker/library/golang:1.18 AS builder
   3 |     WORKDIR /build
--------------------
error: failed to solve: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: error mounting "/tmp/buildkit-metadata342428500" to rootfs at "/run/config/buildkit/metadata": mount /tmp/buildkit-metadata342428500:/run/config/buildkit/metadata (via /proc/self/fd/6), flags: 0x1021: operation not permitted: unknown
FATA[0003] exit status 1                                
siravara@bcd074105a94 syntaxtests % cat Docker
cat: Docker: No such file or directory

Error

error: failed to solve: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: error mounting "/tmp/buildkit-metadata342428500" to rootfs at "/run/config/buildkit/metadata": mount /tmp/buildkit-metadata342428500:/run/config/buildkit/metadata (via /proc/self/fd/6), flags: 0x1021: operation not permitted: unknown
FATA[0003] exit status 1  

Expected behavior
Should build an image.

Screenshots or logs
If applicable, add screenshots or logs to help explain your problem.

Additional context
This ticket is for tracking bug in Buildkit. moby/buildkit#3138

[estesp]

Is this currently solved with 0.4.1 moving to rootfull?

[vsiravar]

Is this currently solved with 0.4.1 moving to rootfull?

Yes, no errors on syntax directive anymore :).

[vsiravar]

Resolved by rootful containerd switch #196.