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Module ID conflict on first dev server compilation

See original GitHub issue

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

Bug

What is the current behavior?

We upgraded all our webpack dependencies (core, dev server and loaders) to their latest versions and started to see modules conflicts on the first compilation using webpack-dev-server:

/* harmony import */ var __WEBPACK_IMPORTED_MODULE_7_desktop_common_img_vendor_logos_songkick_svg__ = __webpack_require__(/*! desktop/common/img/vendor-logos/songkick.svg */ 23);
// ... elsewhere
/* harmony import */ var __WEBPACK_IMPORTED_MODULE_2_desktop_common_js_views_v3_components_core_buttons_Link__ = __webpack_require__(/*! desktop/common/js/views/v3/components/core/buttons/Link */ 23);

These 🔼 are from the same bundle file and they’re referencing the same module ID. The module source for 23 contains the SVG module source, leaving the Link module not present at all in the bundle.

If we change a file and let webpack-dev-server recompile to get the changes, then the bundle correctly contains both the SVG module and the Link module.

This issue is not present when just building the assets with webpack directly.

We tried to downgrade webpack-dev-server back to 2.4.2, but the issue is still presenting itself, so I opened the bug here, since it seems to be a core webpack issue.

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

Unfortunately, any attempts on providing a smaller test case to reproduce this were not possible.

What is the expected behavior?

No module conflicts in the bundle output.

Please mention other relevant information such as the browser version, Node.js version, webpack version and Operating System. Node v8.1.2 webpack 3.5.5 webpack-dev-server 2.7.1 Ubuntu 16.04

Upgraded from the following (which did not present this issue): webpack 2.3.2 webpack-dev-server 2.4.2