Component.Compute: force "real" solve. Fixes #14.

Signed-off-by: Solomon Hykes <sh.github.6811@hykes.org>

dagger/component.go

@@ -41,11 +41,19 @@ func (c *Component) ComputeScript() (*Script, error) {
 }
 
 // Compute the configuration for this component.
-// Note that we simply execute the underlying compute script from an
-// empty filesystem state.
-// (It is never correct to pass an input filesystem state to compute a component)
+//
+// Difference with Execute:
+//
+// 1. Always start with an empty fs state (Execute may receive any state as input)
+// 2. Always solve at the end (Execute is lazy)
+//
 func (c *Component) Compute(ctx context.Context, s Solver, out Fillable) (FS, error) {
-	return c.Execute(ctx, s.Scratch(), out)
+	fs, err := c.Execute(ctx, s.Scratch(), out)
+	if err != nil {
+		return fs, err
+	}
+	_, err = fs.ReadDir(ctx, "/")
+	return fs, err
 }
 
 // A component implements the Executable interface by returning its

examples/repro-14/main.cue

@@ -0,0 +1,13 @@
+package main
+
+www: {
+
+	source: {
+		#dagger: compute: [
+			{
+				do: "fetch-container"
+				ref: "lalalalala",
+			},
+		]
+	}
+}