nodemon: Nodemon crashes with `Cannot read property 'map' of undefined`

nodemon -v: “^1.18.6”
node -v: v10.13.0
Operating system/terminal environment: ubunutu 18.04
Command you ran: npm start in package.json I have “start”: “nodemon”

Expected behaviour

It should run and rerun on changes

Actual behaviour

It errors each time I try to save my changes and gives this

/home/user/projects/mongodb-todo/node_modules/nodemon/lib/monitor/run.js:336 spawn(‘kill’, [‘-s’, sig, child.pid].concat(kids.map(p => p.PID))) ^

TypeError: Cannot read property ‘map’ of undefined at /home/user/projects/mongodb-todo/node_modules/nodemon/lib/monitor/run.js:336:58 at /home/user/projects/mongodb-todo/node_modules/pstree.remy/lib/tree.js:53:11 at ChildProcess.onClose (/home/user/projects/mongodb-todo/node_modules/pstree.remy/lib/tree.js:80:9) at ChildProcess.emit (events.js:182:13) at maybeClose (internal/child_process.js:962:16) at Process.ChildProcess._handle.onexit (internal/child_process.js:251:5) npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! mongodb-todo@1.0.0 start: nodemon npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the mongodb-todo@1.0.0 start script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in: npm ERR! /home/user/.npm/_logs/2018-11-22T12_10_04_952Z-debug.log

Steps to reproduce

install express, morgan, nodemon. run npm start then save changes in app.js

Here is package.json { “name”: “mongodb-todo”, “version”: “1.0.0”, “description”: “”, “main”: “./app.js”, “scripts”: { “test”: “echo "Error: no test specified" && exit 1”, “start”: “nodemon” }, “author”: “”, “license”: “ISC”, “dependencies”: { “express”: “^4.16.4”, “morgan”: “^1.9.1”, “nodemon”: “^1.18.6” } }

If applicable, please append the --dump flag on your command and include the output here ensuring to remove any sensitive/personal details or tokens.

About this issue

Original URL
State: closed
Created 6 years ago
Reactions: 4
Comments: 23 (2 by maintainers)

Commits related to this issue

Bump nodemon to version 1.18.8 A fix to avoid 'crashes with 'Cannot read property 'map' of undefined' https://github.com/remy/nodemon/issues/1459 — committed to linagora/linshare-editor-onlyoffice by deleted user 6 years ago

Most upvoted comments

nodemon dependencies pstree.remy check your package-lock.json
if use “pstree.remy”: “1.1.1”, will has this error use npm i pstree.remy@1.1.0 -D will fix this error I hope I can help you. ：）

cooliean on Nov 23, 2018

Only One Solutiion try this: “npm cache clean --force”

ajay2323 on Oct 31, 2019

Try to use (npm install nodemon).

Fengxusunny on Sep 7, 2020

Fixed and deployed in latest release (going live right now)

remy on Nov 27, 2018

I’m having a similar issue - different error message but nodemon is crashing upon attempting to restart. Node versions: v10.13.0 and v11.2.0 Nodemon version: 1.18.6 and 1.18.3

[nodemon] 1.18.6
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node first-app.js`
rs
/Users/ckunze/src/prof_dev/node-tutorial/node_modules/pstree.remy/lib/tree.js:70
  ps.stdout.on('data', function(data) {
            ^

TypeError: Cannot read property 'on' of undefined
    at buildProcessTree (/Users/ckunze/src/prof_dev/node-tutorial/node_modules/pstree.remy/lib/tree.js:70:13)
    at /Users/ckunze/src/prof_dev/node-tutorial/node_modules/pstree.remy/lib/tree.js:91:7
    at Array.forEach (<anonymous>)
    at ChildProcess.onClose (/Users/ckunze/src/prof_dev/node-tutorial/node_modules/pstree.remy/lib/tree.js:86:27)
    at ChildProcess.emit (events.js:182:13)
    at maybeClose (internal/child_process.js:978:16)
    at Socket.stream.socket.on (internal/child_process.js:395:11)
    at Socket.emit (events.js:182:13)
    at Pipe._handle.close (net.js:616:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! node-tutorial@1.0.0 start: `nodemon first-app.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the node-tutorial@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

Is this related or should I start another issue?

corinnekunze on Nov 25, 2018

Well, I deleted the folder and created everything and it workwd okay…

t-zander on Nov 24, 2018

Guys, instead of posting new issues: Just read/search for already open/closed ones…

sysrun on Nov 22, 2018