yarn upgrade –exact doesn’t work as expected

Do you want to request a feature or report a bug?

bug

What is the current behavior?

It prepend ^ to package version

If the current behavior is a bug, please provide the steps to reproduce.

package.json before upgrade command

devDependencies: {
  "@storybook/addon-actions": "3.2.0",
   "@storybook/addon-centered": "3.2.0",
   "@storybook/addon-info": "3.2.0",
   "@storybook/react": "3.2.3",
}

Run yarn upgrade @storybook/react @storybook/addon-actions @storybook/addon-centered @storybook/addon-info --latest --exact

package.json after upgrade command

devDependencies: {
    "@storybook/addon-actions": "^3.2.6",
    "@storybook/addon-centered": "^3.2.7",
    "@storybook/addon-info": "^3.2.7",
    "@storybook/react": "^3.2.8",
}

What is the expected behavior?

It should respect --exact option.

Please mention your node.js, yarn and operating system version.
node: v8.1.0
yarn: v0.27.5
macOs Sierra: v10.12.6