diff --git a/cmd/dagger/cmd/create.go b/cmd/dagger/cmd/create.go
deleted file mode 100644
index 72f6c6aa..00000000
--- a/cmd/dagger/cmd/create.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package cmd
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-
-	"dagger.cloud/go/dagger/ui"
-	"github.com/spf13/cobra"
-)
-
-var createCmd = &cobra.Command{
-	Use:   "create ENV BASE",
-	Short: "Create an env",
-	Args:  cobra.ExactArgs(2),
-	Run: func(cmd *cobra.Command, args []string) {
-		envname := args[0]
-		base := args[1]
-		envdir := ".dagger/env/" + envname
-		if info, err := os.Stat(envdir); err == nil {
-			if info.IsDir() {
-				ui.Fatalf("env already exists: %s", envname)
-			}
-		}
-		if err := os.MkdirAll(envdir, 0755); err != nil {
-			ui.Fatal(err)
-		}
-		baseCue := fmt.Sprintf("package env\nimport base \"%s\"\nbase\n", base)
-		err := ioutil.WriteFile(envdir+"/base.cue", []byte(baseCue), 0644)
-		if err != nil {
-			ui.Fatal(err)
-		}
-		ui.Info("created environment %q with base %q", envname, base)
-	},
-}
diff --git a/cmd/dagger/cmd/root.go b/cmd/dagger/cmd/root.go
index 81a4638f..23a763aa 100644
--- a/cmd/dagger/cmd/root.go
+++ b/cmd/dagger/cmd/root.go
@@ -14,11 +14,9 @@ func init() {
 	// --debug
 	rootCmd.PersistentFlags().Bool("debug", false, "Enable debug mode")
 	// --workspace
-	rootCmd.PersistentFlags().StringP("workspace", "w", "", "Select workspace")
 	rootCmd.AddCommand(
-		// Create an env
-		createCmd,
 		computeCmd,
+		// Create an env
 		// Change settings on an env
 		// View or edit env serti
 		//		settingsCmd,
diff --git a/dagger/client.go b/dagger/client.go
index da23e426..0dc4f1b0 100644
--- a/dagger/client.go
+++ b/dagger/client.go
@@ -90,7 +90,6 @@ func (c *Client) LocalDirs() ([]string, error) {
 }
 
 func (c *Client) BootScript() (*Script, error) {
-	debugf("compiling boot script: %q\n", c.boot)
 	cc := &Compiler{}
 	src, err := cc.Compile("boot.cue", c.boot)
 	if err != nil {
@@ -147,6 +146,7 @@ func (c *Client) buildfn(ctx context.Context, ch chan *bk.SolveStatus, w io.Writ
 			close(ch)
 			return errors.Wrap(err, "serialize boot script")
 		}
+		debugf("client: assembled boot script: %s\n", bootSource)
 		// Setup solve options
 		opts := bk.SolveOpt{
 			FrontendAttrs: map[string]string{
@@ -193,7 +193,6 @@ func (c *Client) outputfn(_ context.Context, r io.Reader, out *Value) func() err
 		defer debugf("outputfn complete")
 		tr := tar.NewReader(r)
 		for {
-			debugf("outputfn: reading next tar entry")
 			h, err := tr.Next()
 			if err == io.EOF {
 				break
@@ -301,9 +300,12 @@ func (c *Client) printfn(ctx context.Context, ch, ch2 chan *bk.SolveStatus) func
 					len(status.Logs),
 				)
 				for _, v := range status.Vertexes {
+					// FIXME: insert raw buildkit telemetry here (ie for debugging, etc.)
+
+					// IF a buildkit vertex has a valid cue path as name, extract additional info:
 					p := cue.ParsePath(v.Name)
 					if err := p.Err(); err != nil {
-						debugf("ignoring buildkit vertex %q: not a valid cue path", v.Name)
+						// Not a valid cue path: skip.
 						continue
 					}
 					n := &Node{
diff --git a/dagger/compute.go b/dagger/compute.go
index 787b3d6a..046e0b0a 100644
--- a/dagger/compute.go
+++ b/dagger/compute.go
@@ -19,7 +19,6 @@ func Compute(ctx context.Context, c bkgw.Client) (r *bkgw.Result, err error) {
 			debugf("execute returned an error. Wrapping...")
 		}
 	}()
-	debugf("initializing env")
 	// Retrieve boot script form client
 	env, err := NewEnv(ctx, NewSolver(c), getBootScript(c), getInput(c))
 	if err != nil {
diff --git a/dagger/env.go b/dagger/env.go
index 9513694c..66edaa11 100644
--- a/dagger/env.go
+++ b/dagger/env.go
@@ -28,6 +28,7 @@ type Env struct {
 
 // Initialize a new environment
 func NewEnv(ctx context.Context, s Solver, bootsrc, inputsrc string) (*Env, error) {
+	debugf("NewEnv(boot=%q input=%q)", bootsrc, inputsrc)
 	cc := &Compiler{}
 	// 1. Compile & execute boot script
 	boot, err := cc.CompileScript("boot.cue", bootsrc)
@@ -55,6 +56,9 @@ func NewEnv(ctx context.Context, s Solver, bootsrc, inputsrc string) (*Env, erro
 	if _, err := base.Merge(input); err != nil {
 		return nil, errors.Wrap(err, "merge base & input")
 	}
+
+	debugf("ENV: base=%q input=%q", base.JSON(), input.JSON())
+
 	return &Env{
 		base:  base,
 		input: input,
@@ -102,7 +106,7 @@ func (env *Env) Walk(ctx context.Context, fn EnvWalkFunc) (*Value, error) {
 	defer debugf("COMPLETE: Env.Walk")
 	// Cueflow cue instance
 	// FIXME: make this cleaner in *Value by keeping intermediary instances
-	flowInst, err := env.base.CueInst().Fill(env.input.CueInst())
+	flowInst, err := env.base.CueInst().Fill(env.input.CueInst().Value())
 	if err != nil {
 		return nil, err
 	}
diff --git a/dagger/script_test.go b/dagger/script_test.go
index 71898fcc..1c24d1a0 100644
--- a/dagger/script_test.go
+++ b/dagger/script_test.go
@@ -5,6 +5,17 @@ import (
 	"testing"
 )
 
+func TestValidateEmptyValue(t *testing.T) {
+	cc := &Compiler{}
+	v, err := cc.Compile("", "#dagger: compute: _")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := v.Get("#dagger.compute").Validate("#Script"); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestLocalScript(t *testing.T) {
 	cc := &Compiler{}
 	src := `[{do: "local", dir: "foo"}]`
diff --git a/dagger/spec.go b/dagger/spec.go
index ca2db4ec..f84b93d0 100644
--- a/dagger/spec.go
+++ b/dagger/spec.go
@@ -18,7 +18,7 @@ func (s Spec) Validate(v *Value, defpath string) (err error) {
 	// FIXME: there is probably a cleaner way to do this.
 	defer func() {
 		if err != nil {
-			debugf("ERROR while validating %v against %v err=%q", v, defpath, err)
+			//debugf("ERROR while validating %v against %v err=%q", v, defpath, err)
 			err = fmt.Errorf("%s", cueerrors.Details(err, nil))
 		}
 	}()
@@ -33,7 +33,6 @@ func (s Spec) Validate(v *Value, defpath string) (err error) {
 	if err := merged.Err(); err != nil {
 		return err
 	}
-	debugf("Validating %v against %v", v, def)
 	if err := merged.Validate(cue.Final()); err != nil {
 		return err
 	}