cmd/run, sh: Show an error if $PWD is missing inside the container

It might happen that the current working directory in the present
environment is missing inside the container that's going to be used.
So far, Toolbox would fail silently, which wasn't very obvious.

Some changes by Debarshi Ray and Harry Míchal.

#369

src/cmd/run.go

@@ -314,7 +314,11 @@ func runCommand(container string,
 	case 126:
 		err = fmt.Errorf("failed to invoke command %s in container %s", command[0], container)
 	case 127:
-		err = fmt.Errorf("command %s not found in container %s", command[0], container)
+		if pathPresent, _ := isPathPresent(container, workingDirectory); !pathPresent {
+			err = fmt.Errorf("directory %s not found in container %s", workingDirectory, container)
+		} else {
+			err = fmt.Errorf("command %s not found in container %s", command[0], container)
+		}
 	default:
 		err = nil
 	}
@@ -398,6 +402,25 @@ func isCommandPresent(container, command string) (bool, error) {
 	return true, nil
 }
 
+func isPathPresent(container, path string) (bool, error) {
+	logrus.Debugf("Looking for path %s in container %s", path, container)
+
+	logLevelString := podman.LogLevel.String()
+	args := []string{
+		"--log-level", logLevelString,
+		"exec",
+		"--user", currentUser.Username,
+		container,
+		"sh", "-c", "test -d \"$1\"", "sh", path,
+	}
+
+	if err := shell.Run("podman", nil, nil, nil, args...); err != nil {
+		return false, err
+	}
+
+	return true, nil
+}
+
 func startContainer(container string) error {
 	var stderr strings.Builder
 	if err := podman.Start(container, &stderr); err == nil {

toolbox

@@ -1603,6 +1603,16 @@ run()
 
     $emit_escape_sequence && printf "\033]777;container;pop;;\033\\"
 
+    if [ "$ret_val" -eq 127 ] 2>&3; then
+        # shellcheck disable=SC2016
+        if ! $podman_command exec \
+                     --user "$USER" \
+                     "$toolbox_container" \
+                     sh -c 'test -d "$1"' sh "$PWD" >/dev/null 2>&3; then
+            echo "$base_toolbox_command: directory '$PWD' not found in container $toolbox_container" >&2
+        fi
+    fi
+
     exit "$ret_val"
 )