npm / npm/cli

[BUG] Running `npm i` fails with Cannot read properties of null (reading 'isDescendantOf')

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#5,687 opened on Oct 12, 2022 6 comments 2 reactions 0 assignees View on GitHub

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Bug Priority 2 Release 8.x

Dominant language: JavaScript
Stars: 10.1k
Forks: 4.7k
Avg merge: 2d 2h
Merged PRs (30d): 19

Description

Is there an existing issue for this?

I have searched the existing issues

This issue exists in the latest npm version

I am using the latest npm

Current Behavior

When installing a project using PNPM first and then subsequently using standard npm to install it, the install process borks after a long time with:

npm ERR! Cannot read properties of null (reading 'isDescendantOf')

Looking at the generated debug log one can see a null pointer being mentioned:

``` 9918 timing idealTree:node_modules/.pnpm/node_modules/eslint/node_modules/table/node_modules/strip-ansi Completed in 1ms 9919 timing idealTree:node_modules/.pnpm/node_modules/eslint/node_modules/table/node_modules/ansi-regex Completed in 0ms 9920 timing idealTree:node_modules/.pnpm/node_modules/fast-glob/node_modules/glob-parent/node_modules/is-glob Completed in 0ms 9921 timing idealTree Completed in 14547ms 9922 timing command:i Completed in 14573ms 9923 verbose stack TypeError: Cannot read properties of null (reading 'isDescendantOf') 9923 verbose stack at [resolveLinks] (/usr/local/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:1419:37) 9923 verbose stack at [buildDepStep] (/usr/local/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:792:33) 9923 verbose stack at [buildDepStep] (/usr/local/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:1047:31) 9924 verbose cwd /home/carlerik/code/example-encrypt-properties 9925 verbose Linux 5.15.0-47-generic 9926 verbose node v18.10.0 9927 verbose npm v8.19.2 9928 error Cannot read properties of null (reading 'isDescendantOf') 9929 verbose exit 1 9930 timing npm Completed in 14748ms 9931 verbose unfinished npm timer reify 1665582899091 9932 verbose unfinished npm timer reify:loadTrees 1665582899109 9933 verbose unfinished npm timer idealTree:buildDeps 1665582899389 9934 verbose unfinished npm timer idealTree:node_modules/.pnpm/yargs@16.2.0/node_modules/yargs 1665582906713 9935 verbose code 1 9936 error A complete log of this run can be found in: 9936 error /home/carlerik/.npm/_logs/2022-10-12T13_54_58_915Z-debug-0.log ```

Adding a console.log("link.target is null!", link) just before it fails shows this:

This points at one of the PNPM installed files being an issue of some sort. Maybe due to the symlinks created?

Expected Behavior

I would expect that NPM would go about its business and handle the situation where PNPM previously has stepped all over its turf gracefully 😄

It took some attempts (actually writing this) to discover that wiping with rm -r node_modules would fix the issue, so maybe one could add some heuristics to detect weird symlinks where there should not be and just delete the directory before re-installing? That would be very user friendly, at least.

Steps To Reproduce

hub clone fatso83/example-encrypt-properties (clone this repo)
cd example-encrypt-properties && pnpm i && npm i
Observe an error: npm ERR! Cannot read properties of null (reading 'isDescendantOf')

Environment

npm: 7.12.0 (also tested on v6)
Node.js: 18.10.0 (latest, also tested on v16)
OS Name: Ubuntu 22.04.1 LTS
System Model Name: ?
npm config:

; "user" config from /home/carlerik/.npmrc

//registry.npmjs.org/:_authToken = (protected) 
flex-sdk:npm_cmd_ran = "install" 

; node bin location = /usr/local/bin/node
; node version = v18.10.0
; npm local prefix = /home/carlerik/code/nimble
; npm version = 8.19.2
; cwd = /home/carlerik/code/nimble
; HOME = /home/carlerik
; Run `npm config ls -l` to show all defaults.

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Research direction

Reproduce with pnpm i followed by npm i in fatso83/example-encrypt-properties, then inspect @npmcli/arborist/lib/arborist/build-ideal-tree.js around resolveLinks, where the stack trace reports the null access. Done means npm handles the PNPM-created layout without the isDescendantOf error; verify by repeating the reported steps.

Written by the indexing model from the issue text.

Assessment

Tech stack: javascript, nodejs
Domain: cli, tooling
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Stale
Clarity: Mostly clear
Newbie friendliness: 35/100