diff --git a/vendor.conf b/vendor.conf
index eea53c5d85..c50dcf5899 100644
--- a/vendor.conf
+++ b/vendor.conf
@@ -33,7 +33,7 @@ github.com/imdario/mergo                            1afb36080aec31e0d1528973ebe6
 golang.org/x/sync                                   cd5d95a43a6e21273425c7ae415d3df9ea832eeb
 
 # buildkit
-github.com/moby/buildkit                            fcb87e6b8ccf3631a65799cc56caa76f9117816e # v0.8.0-rc2
+github.com/moby/buildkit                            950603da215ae03b843f3f66fbe86c4876a6f5a1
 github.com/tonistiigi/fsutil                        0834f99b7b85462efb69b4f571a4fa3ca7da5ac9
 github.com/tonistiigi/units                         6950e57a87eaf136bbe44ef2ec8e75b9e3569de2
 github.com/grpc-ecosystem/grpc-opentracing          8e809c8a86450a29b90dcc9efbf062d0fe6d9746
diff --git a/vendor/github.com/moby/buildkit/README.md b/vendor/github.com/moby/buildkit/README.md
index 0af9e2e126..4532dd7cde 100644
--- a/vendor/github.com/moby/buildkit/README.md
+++ b/vendor/github.com/moby/buildkit/README.md
@@ -3,8 +3,9 @@
 # BuildKit
 
 [![GoDoc](https://godoc.org/github.com/moby/buildkit?status.svg)](https://godoc.org/github.com/moby/buildkit/client/llb)
-[![Build Status](https://travis-ci.org/moby/buildkit.svg?branch=master)](https://travis-ci.org/moby/buildkit)
+[![Build Status](https://travis-ci.com/moby/buildkit.svg?branch=master)](https://travis-ci.com/moby/buildkit)
 [![Go Report Card](https://goreportcard.com/badge/github.com/moby/buildkit)](https://goreportcard.com/report/github.com/moby/buildkit)
+[![codecov](https://codecov.io/gh/moby/buildkit/branch/master/graph/badge.svg)](https://codecov.io/gh/moby/buildkit)
 
 BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner.
 
diff --git a/vendor/github.com/moby/buildkit/cache/refs.go b/vendor/github.com/moby/buildkit/cache/refs.go
index 2b25235e44..a17f6e10de 100644
--- a/vendor/github.com/moby/buildkit/cache/refs.go
+++ b/vendor/github.com/moby/buildkit/cache/refs.go
@@ -399,8 +399,10 @@ func (sr *immutableRef) Extract(ctx context.Context, s session.Group) (rerr erro
 		ctx = winlayers.UseWindowsLayerMode(ctx)
 	}
 
-	if _, err := sr.prepareRemoteSnapshots(ctx, sr.descHandlers); err != nil {
-		return err
+	if sr.cm.Snapshotter.Name() == "stargz" {
+		if _, err := sr.prepareRemoteSnapshots(ctx, sr.descHandlers); err != nil {
+			return err
+		}
 	}
 
 	return sr.extract(ctx, sr.descHandlers, s)
@@ -454,6 +456,9 @@ func (sr *immutableRef) prepareRemoteSnapshots(ctx context.Context, dhs DescHand
 		// This layer cannot be prepared without unlazying.
 		return false, nil
 	})
+	if err != nil {
+		return false, err
+	}
 	return ok.(bool), err
 }
 
diff --git a/vendor/github.com/moby/buildkit/frontend/dockerfile/builder/build.go b/vendor/github.com/moby/buildkit/frontend/dockerfile/builder/build.go
index f182ae9663..345e789849 100644
--- a/vendor/github.com/moby/buildkit/frontend/dockerfile/builder/build.go
+++ b/vendor/github.com/moby/buildkit/frontend/dockerfile/builder/build.go
@@ -130,8 +130,15 @@ func Build(ctx context.Context, c client.Client) (*client.Result, error) {
 
 	name := "load build definition from " + filename
 
+	filenames := []string{filename, filename + ".dockerignore"}
+
+	// dockerfile is also supported casing moby/moby#10858
+	if path.Base(filename) == defaultDockerfileName {
+		filenames = append(filenames, path.Join(path.Dir(filename), strings.ToLower(defaultDockerfileName)))
+	}
+
 	src := llb.Local(localNameDockerfile,
-		llb.FollowPaths([]string{filename, filename + ".dockerignore"}),
+		llb.FollowPaths(filenames),
 		llb.SessionID(c.BuildOpts().SessionID),
 		llb.SharedKeyHint(localNameDockerfile),
 		dockerfile2llb.WithInternalName(name),
@@ -258,7 +265,19 @@ func Build(ctx context.Context, c client.Client) (*client.Result, error) {
 			Filename: filename,
 		})
 		if err != nil {
-			return errors.Wrapf(err, "failed to read dockerfile")
+			fallback := false
+			if path.Base(filename) == defaultDockerfileName {
+				var err1 error
+				dtDockerfile, err1 = ref.ReadFile(ctx2, client.ReadRequest{
+					Filename: path.Join(path.Dir(filename), strings.ToLower(defaultDockerfileName)),
+				})
+				if err1 == nil {
+					fallback = true
+				}
+			}
+			if !fallback {
+				return errors.Wrapf(err, "failed to read dockerfile")
+			}
 		}
 
 		sourceMap = llb.NewSourceMap(&src, filename, dtDockerfile)
diff --git a/vendor/github.com/moby/buildkit/frontend/gateway/gateway.go b/vendor/github.com/moby/buildkit/frontend/gateway/gateway.go
index 4067f87f10..029468b974 100644
--- a/vendor/github.com/moby/buildkit/frontend/gateway/gateway.go
+++ b/vendor/github.com/moby/buildkit/frontend/gateway/gateway.go
@@ -255,7 +255,7 @@ func (gf *gatewayFrontend) Solve(ctx context.Context, llbBridge frontend.Fronten
 	err = w.Executor().Run(ctx, "", mountWithSession(rootFS, session.NewGroup(sid)), nil, executor.ProcessInfo{Meta: meta, Stdin: lbf.Stdin, Stdout: lbf.Stdout, Stderr: os.Stderr}, nil)
 
 	if err != nil {
-		if errors.Is(err, context.Canceled) && lbf.isErrServerClosed {
+		if errdefs.IsCanceled(err) && lbf.isErrServerClosed {
 			err = errors.Errorf("frontend grpc server closed unexpectedly")
 		}
 		// An existing error (set via Return rpc) takes
diff --git a/vendor/github.com/moby/buildkit/solver/edge.go b/vendor/github.com/moby/buildkit/solver/edge.go
index 6ebf3a74db..125c55fcfe 100644
--- a/vendor/github.com/moby/buildkit/solver/edge.go
+++ b/vendor/github.com/moby/buildkit/solver/edge.go
@@ -359,6 +359,7 @@ func (e *edge) unpark(incoming []pipe.Sender, updates, allPipes []pipe.Receiver,
 	if e.execReq == nil {
 		if added := e.createInputRequests(desiredState, f, false); !added && !e.hasActiveOutgoing && !cacheMapReq {
 			logrus.Errorf("buildkit scheluding error: leaving incoming open. forcing solve. Please report this with BUILDKIT_SCHEDULER_DEBUG=1")
+			debugSchedulerPreUnpark(e, incoming, updates, allPipes)
 			e.createInputRequests(desiredState, f, true)
 		}
 	}
diff --git a/vendor/github.com/moby/buildkit/solver/errdefs/context.go b/vendor/github.com/moby/buildkit/solver/errdefs/context.go
new file mode 100644
index 0000000000..ea6bdfbf09
--- /dev/null
+++ b/vendor/github.com/moby/buildkit/solver/errdefs/context.go
@@ -0,0 +1,13 @@
+package errdefs
+
+import (
+	"context"
+	"errors"
+
+	"github.com/moby/buildkit/util/grpcerrors"
+	"google.golang.org/grpc/codes"
+)
+
+func IsCanceled(err error) bool {
+	return errors.Is(err, context.Canceled) || grpcerrors.Code(err) == codes.Canceled
+}
diff --git a/vendor/github.com/moby/buildkit/solver/jobs.go b/vendor/github.com/moby/buildkit/solver/jobs.go
index 932d9d0f1e..67f1a30f94 100644
--- a/vendor/github.com/moby/buildkit/solver/jobs.go
+++ b/vendor/github.com/moby/buildkit/solver/jobs.go
@@ -659,6 +659,7 @@ func (s *sharedOp) CalcSlowCache(ctx context.Context, index Index, p PreprocessF
 			case <-ctx.Done():
 				if strings.Contains(err.Error(), context.Canceled.Error()) {
 					complete = false
+					releaseError(err)
 					err = errors.Wrap(ctx.Err(), err.Error())
 				}
 			default:
@@ -717,6 +718,7 @@ func (s *sharedOp) CacheMap(ctx context.Context, index int) (resp *cacheMapResp,
 			case <-ctx.Done():
 				if strings.Contains(err.Error(), context.Canceled.Error()) {
 					complete = false
+					releaseError(err)
 					err = errors.Wrap(ctx.Err(), err.Error())
 				}
 			default:
@@ -774,6 +776,7 @@ func (s *sharedOp) Exec(ctx context.Context, inputs []Result) (outputs []Result,
 			case <-ctx.Done():
 				if strings.Contains(err.Error(), context.Canceled.Error()) {
 					complete = false
+					releaseError(err)
 					err = errors.Wrap(ctx.Err(), err.Error())
 				}
 			default:
@@ -911,3 +914,15 @@ func WrapSlowCache(err error, index Index, res Result) error {
 	}
 	return &SlowCacheError{Index: index, Result: res, error: err}
 }
+
+func releaseError(err error) {
+	if err == nil {
+		return
+	}
+	if re, ok := err.(interface {
+		Release() error
+	}); ok {
+		re.Release()
+	}
+	releaseError(errors.Unwrap(err))
+}
diff --git a/vendor/github.com/moby/buildkit/solver/llbsolver/bridge.go b/vendor/github.com/moby/buildkit/solver/llbsolver/bridge.go
index 52a88a2364..e6a5850fef 100644
--- a/vendor/github.com/moby/buildkit/solver/llbsolver/bridge.go
+++ b/vendor/github.com/moby/buildkit/solver/llbsolver/bridge.go
@@ -16,6 +16,7 @@ import (
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/solver"
 	"github.com/moby/buildkit/solver/errdefs"
+	llberrdefs "github.com/moby/buildkit/solver/llbsolver/errdefs"
 	"github.com/moby/buildkit/solver/pb"
 	"github.com/moby/buildkit/util/flightcontrol"
 	"github.com/moby/buildkit/worker"
@@ -144,41 +145,60 @@ func (b *llbBridge) Solve(ctx context.Context, req frontend.SolveRequest, sid st
 }
 
 type resultProxy struct {
-	cb       func(context.Context) (solver.CachedResult, error)
-	def      *pb.Definition
-	g        flightcontrol.Group
-	mu       sync.Mutex
-	released bool
-	v        solver.CachedResult
-	err      error
+	cb         func(context.Context) (solver.CachedResult, error)
+	def        *pb.Definition
+	g          flightcontrol.Group
+	mu         sync.Mutex
+	released   bool
+	v          solver.CachedResult
+	err        error
+	errResults []solver.Result
 }
 
 func newResultProxy(b *llbBridge, req frontend.SolveRequest) *resultProxy {
-	return &resultProxy{
+	rp := &resultProxy{
 		def: req.Definition,
-		cb: func(ctx context.Context) (solver.CachedResult, error) {
-			return b.loadResult(ctx, req.Definition, req.CacheImports)
-		},
 	}
+	rp.cb = func(ctx context.Context) (solver.CachedResult, error) {
+		res, err := b.loadResult(ctx, req.Definition, req.CacheImports)
+		var ee *llberrdefs.ExecError
+		if errors.As(err, &ee) {
+			ee.EachRef(func(res solver.Result) error {
+				rp.errResults = append(rp.errResults, res)
+				return nil
+			})
+			// acquire ownership so ExecError finalizer doesn't attempt to release as well
+			ee.OwnerBorrowed = true
+		}
+		return res, err
+	}
+	return rp
 }
 
 func (rp *resultProxy) Definition() *pb.Definition {
 	return rp.def
 }
 
-func (rp *resultProxy) Release(ctx context.Context) error {
+func (rp *resultProxy) Release(ctx context.Context) (err error) {
 	rp.mu.Lock()
 	defer rp.mu.Unlock()
+	for _, res := range rp.errResults {
+		rerr := res.Release(ctx)
+		if rerr != nil {
+			err = rerr
+		}
+	}
 	if rp.v != nil {
 		if rp.released {
 			logrus.Warnf("release of already released result")
 		}
-		if err := rp.v.Release(ctx); err != nil {
-			return err
+		rerr := rp.v.Release(ctx)
+		if err != nil {
+			return rerr
 		}
 	}
 	rp.released = true
-	return nil
+	return
 }
 
 func (rp *resultProxy) wrapError(err error) error {
diff --git a/vendor/github.com/moby/buildkit/solver/llbsolver/errdefs/exec.go b/vendor/github.com/moby/buildkit/solver/llbsolver/errdefs/exec.go
index 0a41792db2..f60757104f 100644
--- a/vendor/github.com/moby/buildkit/solver/llbsolver/errdefs/exec.go
+++ b/vendor/github.com/moby/buildkit/solver/llbsolver/errdefs/exec.go
@@ -1,14 +1,19 @@
 package errdefs
 
 import (
+	"context"
+	"runtime"
+
 	"github.com/moby/buildkit/solver"
+	"github.com/sirupsen/logrus"
 )
 
 // ExecError will be returned when an error is encountered when evaluating an op.
 type ExecError struct {
 	error
-	Inputs []solver.Result
-	Mounts []solver.Result
+	Inputs        []solver.Result
+	Mounts        []solver.Result
+	OwnerBorrowed bool
 }
 
 func (e *ExecError) Unwrap() error {
@@ -35,13 +40,35 @@ func (e *ExecError) EachRef(fn func(solver.Result) error) (err error) {
 	return err
 }
 
+func (e *ExecError) Release() error {
+	if e.OwnerBorrowed {
+		return nil
+	}
+	err := e.EachRef(func(r solver.Result) error {
+		r.Release(context.TODO())
+		return nil
+	})
+	e.OwnerBorrowed = true
+	return err
+}
+
 func WithExecError(err error, inputs, mounts []solver.Result) error {
 	if err == nil {
 		return nil
 	}
-	return &ExecError{
+	ee := &ExecError{
 		error:  err,
 		Inputs: inputs,
 		Mounts: mounts,
 	}
+	runtime.SetFinalizer(ee, func(e *ExecError) {
+		if !e.OwnerBorrowed {
+			e.EachRef(func(r solver.Result) error {
+				logrus.Warn("leaked execError detected and released")
+				r.Release(context.TODO())
+				return nil
+			})
+		}
+	})
+	return ee
 }
diff --git a/vendor/github.com/moby/buildkit/solver/llbsolver/mounts/mount.go b/vendor/github.com/moby/buildkit/solver/llbsolver/mounts/mount.go
index f9e3db8995..05703acab5 100644
--- a/vendor/github.com/moby/buildkit/solver/llbsolver/mounts/mount.go
+++ b/vendor/github.com/moby/buildkit/solver/llbsolver/mounts/mount.go
@@ -178,6 +178,9 @@ func (mm *MountManager) getSSHMountable(ctx context.Context, m *pb.Mount, g sess
 	if err != nil {
 		return nil, err
 	}
+	if caller == nil {
+		return nil, nil
+	}
 	// because ssh socket remains active, to actually handle session disconnecting ssh error
 	// should restart the whole exec with new session
 	return &sshMount{mount: m, caller: caller, idmap: mm.cm.IdentityMapping()}, nil
diff --git a/vendor/github.com/moby/buildkit/solver/llbsolver/solver.go b/vendor/github.com/moby/buildkit/solver/llbsolver/solver.go
index 1413bc8c06..d3ef585284 100644
--- a/vendor/github.com/moby/buildkit/solver/llbsolver/solver.go
+++ b/vendor/github.com/moby/buildkit/solver/llbsolver/solver.go
@@ -16,7 +16,6 @@ import (
 	"github.com/moby/buildkit/frontend/gateway"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/solver"
-	"github.com/moby/buildkit/solver/llbsolver/errdefs"
 	"github.com/moby/buildkit/util/compression"
 	"github.com/moby/buildkit/util/entitlements"
 	"github.com/moby/buildkit/util/progress"
@@ -143,20 +142,6 @@ func (s *Solver) Solve(ctx context.Context, id string, sessionID string, req fro
 	res.EachRef(func(ref solver.ResultProxy) error {
 		eg.Go(func() error {
 			_, err := ref.Result(ctx2)
-			if err != nil {
-				// Also release any results referenced by exec errors.
-				var ee *errdefs.ExecError
-				if errors.As(err, &ee) {
-					ee.EachRef(func(res solver.Result) error {
-
-						workerRef, ok := res.Sys().(*worker.WorkerRef)
-						if !ok {
-							return nil
-						}
-						return workerRef.ImmutableRef.Release(ctx)
-					})
-				}
-			}
 			return err
 		})
 		return nil
diff --git a/vendor/github.com/moby/buildkit/solver/scheduler.go b/vendor/github.com/moby/buildkit/solver/scheduler.go
index 7fe981eff4..5b598bd6b9 100644
--- a/vendor/github.com/moby/buildkit/solver/scheduler.go
+++ b/vendor/github.com/moby/buildkit/solver/scheduler.go
@@ -130,9 +130,13 @@ func (s *scheduler) dispatch(e *edge) {
 	pf := &pipeFactory{s: s, e: e}
 
 	// unpark the edge
-	debugSchedulerPreUnpark(e, inc, updates, out)
+	if debugScheduler {
+		debugSchedulerPreUnpark(e, inc, updates, out)
+	}
 	e.unpark(inc, updates, out, pf)
-	debugSchedulerPostUnpark(e, inc)
+	if debugScheduler {
+		debugSchedulerPostUnpark(e, inc)
+	}
 
 postUnpark:
 	// set up new requests that didn't complete/were added by this run
@@ -361,9 +365,6 @@ func (pf *pipeFactory) NewFuncRequest(f func(context.Context) (interface{}, erro
 }
 
 func debugSchedulerPreUnpark(e *edge, inc []pipe.Sender, updates, allPipes []pipe.Receiver) {
-	if !debugScheduler {
-		return
-	}
 	logrus.Debugf(">> unpark %s req=%d upt=%d out=%d state=%s %s", e.edge.Vertex.Name(), len(inc), len(updates), len(allPipes), e.state, e.edge.Vertex.Digest())
 
 	for i, dep := range e.deps {
@@ -371,7 +372,7 @@ func debugSchedulerPreUnpark(e *edge, inc []pipe.Sender, updates, allPipes []pip
 		if dep.req != nil {
 			des = dep.req.Request().(*edgeRequest).desiredState
 		}
-		logrus.Debugf(":: dep%d %s state=%s des=%s keys=%d hasslowcache=%v", i, e.edge.Vertex.Inputs()[i].Vertex.Name(), dep.state, des, len(dep.keys), e.slowCacheFunc(dep) != nil)
+		logrus.Debugf(":: dep%d %s state=%s des=%s keys=%d hasslowcache=%v preprocessfunc=%v", i, e.edge.Vertex.Inputs()[i].Vertex.Name(), dep.state, des, len(dep.keys), e.slowCacheFunc(dep) != nil, e.preprocessFunc(dep) != nil)
 	}
 
 	for i, in := range inc {
@@ -400,9 +401,6 @@ func debugSchedulerPreUnpark(e *edge, inc []pipe.Sender, updates, allPipes []pip
 }
 
 func debugSchedulerPostUnpark(e *edge, inc []pipe.Sender) {
-	if !debugScheduler {
-		return
-	}
 	for i, in := range inc {
 		logrus.Debugf("< incoming-%d: %p completed=%v", i, in, in.Status().Completed)
 	}