Skip to main content

Angular 5 Build issues - Cannot find module 'webpack/lib/dependencies/ContextElementDependency'

After upgrading to Node.js version 8 on our build server, one of our development teams contacted me because their build started to fail. Here is the error they got when running ‘ng build’:

2018-06-14T06:20:11.8790352Z ##[section]Starting: ng build

2018-06-14T06:20:11.9073421Z ==============================================================================

2018-06-14T06:20:11.9073421Z Task         : npm

2018-06-14T06:20:11.9073421Z Description  : Run an npm command

2018-06-14T06:20:11.9083182Z Version      : 0.2.22

2018-06-14T06:20:11.9083182Z Author       : Microsoft Corporation

2018-06-14T06:20:11.9083182Z Help         : [More Information](https://go.microsoft.com/fwlink/?LinkID=613746)

2018-06-14T06:20:11.9083182Z ==============================================================================

2018-06-14T06:20:15.5560039Z [command]C:\Program Files\nodejs\npm.cmd config list

2018-06-14T06:20:17.1849642Z ; cli configs

2018-06-14T06:20:17.1849642Z metrics-registry = "https://registry.npmjs.org/"

2018-06-14T06:20:17.1849642Z scope = ""

2018-06-14T06:20:17.1849642Z user-agent = "npm/5.6.0 node/v8.11.2 win32 x64"

2018-06-14T06:20:17.1849642Z

2018-06-14T06:20:17.1849642Z ; builtin config undefined

2018-06-14T06:20:17.1859408Z prefix = "C:\\Users\\AppData\\Roaming\\npm"

2018-06-14T06:20:17.1859408Z

2018-06-14T06:20:17.1859408Z ; node bin location = C:\Program Files\nodejs\node.exe

2018-06-14T06:20:17.1859408Z ; cwd = D:\b\3\_work\8\s\BBM

2018-06-14T06:20:17.1859408Z ; HOME = C:\Users\

2018-06-14T06:20:17.1859408Z ; "npm config ls -l" to show all defaults.

2018-06-14T06:20:17.1869174Z

2018-06-14T06:20:17.2357474Z [command]C:\Program Files\nodejs\npm.cmd run ng build

2018-06-14T06:20:20.5014978Z

2018-06-14T06:20:20.5014978Z > BBM@0.0.0 ng D:\b\3\_work\8\s\BBM

2018-06-14T06:20:20.5171234Z > ng "build"

2018-06-14T06:20:20.5171234Z

2018-06-14T06:20:30.8837324Z Cannot find module 'webpack/lib/dependencies/ContextElementDependency'

2018-06-14T06:20:30.8837324Z Error: Cannot find module 'webpack/lib/dependencies/ContextElementDependency'

2018-06-14T06:20:30.8837324Z     at Function.Module._resolveFilename (module.js:547:15)

2018-06-14T06:20:30.8837324Z     at Function.Module._load (module.js:474:25)

2018-06-14T06:20:30.8837324Z     at Module.require (module.js:596:17)

2018-06-14T06:20:30.8837324Z     at require (internal/module.js:11:18)

2018-06-14T06:20:30.8837324Z     at Object.<anonymous> (D:\b\3\_work\8\s\BBM\node_modules\@ngtools\webpack\src\plugin.js:8:34)

2018-06-14T06:20:30.8837324Z     at Module._compile (module.js:652:30)

2018-06-14T06:20:30.8837324Z     at Object.Module._extensions..js (module.js:663:10)

2018-06-14T06:20:30.8837324Z     at Module.load (module.js:565:32)

2018-06-14T06:20:30.8837324Z     at tryModuleLoad (module.js:505:12)

2018-06-14T06:20:30.8837324Z     at Function.Module._load (module.js:497:3)

2018-06-14T06:20:30.9325624Z npm ERR! code ELIFECYCLE

2018-06-14T06:20:30.9325624Z npm ERR! errno 1

2018-06-14T06:20:30.9345156Z npm ERR! BBM@0.0.0 ng: `ng "build"`

2018-06-14T06:20:30.9345156Z npm ERR! Exit status 1

2018-06-14T06:20:30.9345156Z npm ERR!

2018-06-14T06:20:30.9354922Z npm ERR! Failed at the BBM@0.0.0 ng script.

2018-06-14T06:20:30.9354922Z npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

2018-06-14T06:20:30.9520944Z

2018-06-14T06:20:30.9520944Z npm ERR! A complete log of this run can be found in:

2018-06-14T06:20:30.9520944Z npm ERR!     C:\Users\AppData\Roaming\npm-cache\_logs\2018-06-14T06_20_30_933Z-debug.log

2018-06-14T06:20:31.3720324Z ##[error]npm failed with error: C:\Program Files\nodejs\npm.cmd failed with return code: 1

2018-06-14T06:20:31.3720324Z ##[section]Finishing: ng build

Here are the steps we took to fix it:

  • Step 1  - Deleted the node modules from the build folder
  • Step 2 – Removed the existing package-lock.json
  • Step 3 - Run npm install
  • Step 4 – Check in the newly created package-lock.json

After doing that, the build started to work again. (My love/hate relationship with NPM continues…Smile)

Popular posts from this blog

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...

Cache stampede: when our cache turned against us

While investigating some performance issues, we ran into an ASP.NET Core API that cached a fairly expensive aggregation query for 60 seconds. Under normal load, that was fine: one request rebuilds the cache, everyone else reads from it. Under peak load, dozens of requests would arrive in that same expiry window, all see a cache miss, and all fire the same expensive query in parallel. The database didn't like that. That was the moment when our caching layer stopped helping and started hurting. A burst of requests comes in at the same time, all miss the cache, and all go hammer the database or the downstream API at once. That's a cache stampede . The cache was supposed to protect our backend, and for a few hundred milliseconds it did the opposite. Why this happens IMemoryCache.GetOrCreate (and its async sibling) looks like it protects you, but it doesn't add any locking on its own. Look at the naive version: public async Task<Report> GetReportAsync(string key) ...

A complex system designed from scratch never works

A few years ago, I worked as an architect on a big mainframe rewrite. I still count it as one of my failures. Not because the technology was wrong, but because I couldn't convince the management team to simplify the approach. Years later, the organization is still struggling to get the new system up and running. I left the project at the time, because I couldn't put my name behind an approach that would take very long and cost a lot of money without a working system to show for it along the way. Gall’s Law That memory keeps coming back to me, because it's a textbook case of Gall's Law playing out in real life. Gall's Law , from John Gall's Systemantics , states it plainly: A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works, and it cannot be patched to make it work. You have to start over with a simple system that works. What does that mean in practice,...