# Cached builds result in MODULE\_NOT\_FOUND **URL:** \ **Category:** Node.js\ **Created:** [January 15, 2019, 10:07pm UTC](https://travis-ci.community/t/cached-builds-result-in-module-not-found/1861 "2019-01-15T22:07:00Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![bobvanderlinden](https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/bobvanderlinden/32/973_2.png) [@bobvanderlinden](https://travis-ci.community/u/bobvanderlinden)\ **Post date:** [January 15, 2019, 10:07pm UTC](https://travis-ci.community/t/cached-builds-result-in-module-not-found/1861/1 "2019-01-15T22:07:00Z")
Every time I build my project using `cache: npm` it will fail after files are cached. The error upon failure is: ```auto $ npm ci npm WARN prepare removing existing node_modules/ before installation npm ERR! code MODULE_NOT_FOUND npm ERR! Cannot find module '../pack.js' npm ERR! A complete log of this run can be found in: npm ERR! /home/travis/.npm/_logs/2019-01-15T21_56_06_702Z-debug.log ``` One clue is that uncached builds are using `npm install` whereas builds where the cache already exists will use `npm ci`. The configuration I’m using is: ```auto language: node_js node_js: - '8.3' cache: npm ... ``` (see [https://github.com/bobvanderlinden/probot-auto-merge/blob/master/.travis.yml](https://github.com/bobvanderlinden/probot-auto-merge/blob/master/.travis.yml)) My repository has `package-lock.json`: [https://github.com/bobvanderlinden/probot-auto-merge/blob/master/package-lock.json](https://github.com/bobvanderlinden/probot-auto-merge/blob/master/package-lock.json) My latest build of `master` shows the problem quite well. I’m using multiple stages. The first stage passes and thus generates a cache, but the second one will use the cache and fails. See [https://travis-ci.com/bobvanderlinden/probot-auto-merge/builds/97343245](https://travis-ci.com/bobvanderlinden/probot-auto-merge/builds/97343245) I’ve tried to delete all cache files multiple times and have tried different configuration options, but I thought the current one is the most minimal and simple and I was thinking this should just work according to the documentation. I was about to drop caching altogether, but I thought I first ask here for help. Does anyone have any idea how to get this working correctly or why it is failing? ---
**Author:** ![BanzaiMan](https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/banzaiman/32/67_2.png) [@BanzaiMan](https://travis-ci.community/u/BanzaiMan)\ **Post date:** [January 16, 2019, 12:52am UTC](https://travis-ci.community/t/cached-builds-result-in-module-not-found/1861/2 "2019-01-16T00:52:37Z")
It seems to me a combination of things. First, notice that you are choosing `node_js: 8.3` with `cache: npm` in [https://github.com/bobvanderlinden/probot-auto-merge/blob/fbf3335a96e106d079fb3a93c495bf6abe54afe/.travis.yml](https://github.com/bobvanderlinden/probot-auto-merge/blob/fbf3335a96e106d079fb3a93c495bf6abe54afe/.travis.yml). Second, in [the initial job](https://travis-ci.com/bobvanderlinden/probot-auto-merge/jobs/170419821#L446), you see that `npm` version is one that comes with Node.js 8.3.0, which is 5.3.0. This is too old to support `npm ci`, so the default dependency installation command is [`npm install`](https://travis-ci.com/bobvanderlinden/probot-auto-merge/jobs/170419821#L450). Third, in [the second job](https://travis-ci.com/bobvanderlinden/probot-auto-merge/jobs/170419822#L445), however, `npm --version` shows 6.5.0. It is not clear to me why. I would imagine that this is because of the use of the cache from the previous job, since on the outset of this job, `npm --version` _clearly_ shows [5.3.0](https://travis-ci.com/bobvanderlinden/probot-auto-merge/jobs/170419822#L430). The newer version now informs a different installation command `npm ci`; this would not work because the directory we have cached is [`npm_modules`](https://travis-ci.com/bobvanderlinden/probot-auto-merge/jobs/170419822#L440), whereas it is expecting to find things in `$HOME/.npm` (because the [`package-lock.json` file exists](https://github.com/bobvanderlinden/probot-auto-merge/blob/fbf3335a96e106d079fb3a93c495b8f6abe54afe/package-lock.json)). This sort of npm switching is not anticipated by our build script, and it seems too unwieldy to really cope with. It is not clear to me how best to deal with the problem, as I am not familiar with the Node.js ecosystem and its best practices. However, I can suggest a few potential solutions (in no particular order). 1. Use a more recent Node.js version. Presumably one that has a recent version of npm that can handle the `ci` subcommand should behave well. (I don’t know how recent is “recent enough.”) 2. Update `npm` in `before_install` to a version at least 5.8.0. This should ensure consistent `install` behavior. 3. Identify the reason that `npm` 6.5.0 is in use in the second job, and rectify. This, too, should ensure consistent behavior. 4. Remove `package-lock.json` from the repository. This should force the use of `npm install` even when npm is recent enough to handle the `ci` subcommand. Not every one of these might work, and they may exhibit different characteristics and benefits (e.g., presumably `npm ci` is faster than `npm install` [https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable](https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable)). I suggest working out the solution that works best for you. ---
**Author:** ![bobvanderlinden](https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/bobvanderlinden/32/973_2.png) [@bobvanderlinden](https://travis-ci.community/u/bobvanderlinden)\ **Post date:** [January 19, 2019, 12:41pm UTC](https://travis-ci.community/t/cached-builds-result-in-module-not-found/1861/3 "2019-01-19T12:41:25Z")
Thank you! Upgrading NodeJS to the latest LTS worked for me! 👍 ---
**Author:** ![BanzaiMan](https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/banzaiman/32/67_2.png) [@BanzaiMan](https://travis-ci.community/u/BanzaiMan)\ **Post date:** [January 19, 2019, 3:49pm UTC](https://travis-ci.community/t/cached-builds-result-in-module-not-found/1861/4 "2019-01-19T15:49:15Z")
Great to hear you were able to resolve it.