cli: make cli.StatusError slightly prettier

cli/command/network/remove_test.go

@@ -90,7 +90,7 @@ func TestNetworkRemoveForce(t *testing.T) {
 				assert.NilError(t, err)
 			} else {
 				assert.Check(t, is.Contains(fakeCli.ErrBuffer().String(), tc.expectedErr))
-				assert.ErrorContains(t, err, "Code: 1")
+				assert.ErrorContains(t, err, "exit status 1")
 			}
 		})
 	}

cli/command/system/info_test.go

@@ -444,7 +444,7 @@ func TestFormatInfo(t *testing.T) {
 		{
 			doc:           "syntax",
 			template:      "{{}",
-			expectedError: `Status: template parsing error: template: :1: unexpected "}" in command, Code: 64`,
+			expectedError: `template parsing error: template: :1: unexpected "}" in command`,
 		},
 		{
 			doc:           "syntax",

cli/error.go

@@ -1,7 +1,7 @@
 package cli
 
 import (
-	"fmt"
+	"strconv"
 	"strings"
 )
 
@@ -28,6 +28,12 @@ type StatusError struct {
 	StatusCode int
 }
 
+// Error formats the error for printing. If a custom Status is provided,
+// it is returned as-is, otherwise it generates a generic error-message
+// based on the StatusCode.
 func (e StatusError) Error() string {
-	return fmt.Sprintf("Status: %s, Code: %d", e.Status, e.StatusCode)
+	if e.Status == "" {
+		return "exit status " + strconv.Itoa(e.StatusCode)
+	}
+	return e.Status
 }