react-native: Babel error: "Error: We don't know what to do with this node type. We were previously a Statement but we can't fit in here?"

• Review the documentation: https://facebook.github.io/react-native
• Search for existing issues: https://github.com/facebook/react-native/issues
• Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

  React Native Environment Info:
    System:
      OS: Linux 4.15 Ubuntu 18.04 LTS (Bionic Beaver)
      CPU: x64 AMD FX(tm)-6300 Six-Core Processor
      Memory: 4.52 GB / 31.32 GB
      Shell: 4.4.19 - /bin/bash
    Binaries:
      Node: 10.4.0 - ~/.nvm/versions/node/v10.4.0/bin/node
      npm: 6.1.0 - ~/.nvm/versions/node/v10.4.0/bin/npm
      Watchman: 4.9.0 - /usr/local/bin/watchman
    SDKs:
      Android SDK:
        Build Tools: 23.0.1, 25.0.0, 25.0.2, 25.0.3, 26.0.1, 26.0.2, 27.0.3
        API Levels: 23, 25, 26, 27
    npmPackages:
      @client/react: ^1.0.13 => 1.0.63 
      @client/react-native: ^1.0.13 => 1.0.63 
      react-native: ^0.56.0 => 0.56.0 

Description

With Webpack, everything works fine. With react-native, it fails, using the same Babel setup except that I use babel-preset-react-native instead of @babel/preset-env. Other Babel config:

Internal preset

presets: [
	['babel-preset-react-native', { decoratorsLegacy: true }]
	// or
	['@babel/preset-env', { target: { browser: /* ... */ } }]
],
plugins: [
	'@babel/plugin-transform-flow-comments',
	'@babel/plugin-transform-react-jsx',
	'@babel/plugin-proposal-object-rest-spread',
	'@babel/plugin-syntax-dynamic-import',
	'babel-plugin-lodash',
	['@babel/plugin-proposal-decorators', { legacy: true }],
	['@babel/plugin-proposal-class-properties', { loose: true}],
]

.babelrc

{
  "presets": [
    [
      "witkit-client",
      {}
    ]
  ],
  "plugins": [
    "transform-inline-environment-variables",
    "babel-plugin-transform-flow-strip-types",
    [
      "module-resolver",
      {
        "root": [
          "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root"
        ],
        "alias": {
          "fs": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/shim/empty",
          "path": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/shim/empty",
          "node-localstorage": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/shim/empty",
          "stream": "stream-browserify",
          "vm": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/shim/empty",
          "modernizr.*$": "@client/modernizr",
          "browsernizr.*$": "@client/modernizr",
          "elk-theme-list": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/cache/react-native-theme-list.js",
          "react-addons-shallow-compare": "shallow-compare",
          "react-dom/lib/CSSProperty": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/shim/react-dom-css-property",
          "react/lib/ReactPropTypes": "prop-types",
          "@client/account-settings/settings/versions/versions.native.js": "/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/cache/VersionList.native.js"
        }
      }
    ]
  ]
}

Error:

Loading dependency graph, done.
error: bundling failed: Error: We don't know what to do with this node type. We were previously a Statement but we can't fit in here?
    at NodePath.insertBefore (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/path/modification.js:55:11)
    at PluginPass.Class (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/plugin-proposal-class-properties/lib/index.js:257:14)
    at newFn (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/visitors.js:237:21)
    at NodePath._call (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/path/context.js:65:20)
    at NodePath.call (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/path/context.js:100:12)
    at TraversalContext.visitQueue (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/context.js:142:16)
    at TraversalContext.visitSingle (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/context.js:102:19)
    at TraversalContext.visit (/mnt/scratch/shared/petter/witkit-devenv/client-react-native-0.56/root/node_modules/@babel/traverse/lib/context.js:182:19)

Unfortunately I do not have a demo and can’t share the (proprietary) source, but any suggestions on how to go about debugging this would be welcome.

It seems likely that this is related to the decorators plugin, but the relevant stuff seems to work fine in Webpack but fail with RN, in spite of using the same config for decorators and class-props plugins, the same version of all the @babel/ packages (pinned to the same 7.0.0-beta.47 as babel-preset-react-native), &c.