gatsby: [gatsby-plugin-netlify-cms]: Cannot find module 'uglifyjs-webpack-plugin'

Description

I tried rebuilding my project but couldn’t. gatsby develop and gatsby build give the same error. If I add uglifyjs-webpack-plugin the project builds without errors. I didn’t change any code since my last successful build, nor could I find any recent commits referring to this module.

Expected result

Build

Actual result

Buildn’t

Environment

  System:
    OS: macOS 10.14.1
    CPU: (4) x64 Intel(R) Core(TM) i5-6360U CPU @ 2.00GHz
    Shell: 5.3 - /bin/zsh
  Binaries:
    Node: 11.2.0 - ~/.nvm/versions/node/v11.2.0/bin/node
    npm: 6.4.1 - ~/.nvm/versions/node/v11.2.0/bin/npm
  Browsers:
    Chrome: 70.0.3538.110
    Firefox: 63.0.3
    Safari: 12.0.1
  npmPackages:
    gatsby: ^2.0.53 => 2.0.53 
    gatsby-image: ^2.0.20 => 2.0.20 
    gatsby-plugin-canonical-urls: ^2.0.7 => 2.0.7 
    gatsby-plugin-create-client-paths: ^2.0.2 => 2.0.2 
    gatsby-plugin-feed: ^2.0.9 => 2.0.9 
    gatsby-plugin-gtag: ^1.0.4 => 1.0.4 
    gatsby-plugin-manifest: ^2.0.9 => 2.0.9 
    gatsby-plugin-netlify: ^2.0.5 => 2.0.5 
    gatsby-plugin-netlify-cache: ^1.0.0 => 1.0.0 
    gatsby-plugin-netlify-cms: ^3.0.7 => 3.0.7 
    gatsby-plugin-no-sourcemaps: ^2.0.1 => 2.0.1 
    gatsby-plugin-offline: ^2.0.16 => 2.0.16 
    gatsby-plugin-react-helmet: ^3.0.2 => 3.0.2 
    gatsby-plugin-robots-txt: ^1.3.0 => 1.3.0 
    gatsby-plugin-sharp: ^2.0.12 => 2.0.12 
    gatsby-plugin-sitemap: ^2.0.2 => 2.0.2 
    gatsby-plugin-styled-components: ^3.0.3 => 3.0.3 
    gatsby-remark-images: ^2.0.6 => 2.0.6 
    gatsby-source-filesystem: ^2.0.8 => 2.0.8 
    gatsby-transformer-remark: ^2.1.12 => 2.1.12 
    gatsby-transformer-sharp: ^2.1.8 => 2.1.8 
  npmGlobalPackages:
    gatsby-cli: 2.4.5