"Path must be a string. Received undefined"

[UTGuy]

• npm v5.51
• node v8.9.0

... it seems that anytime I run an npx command it shows "Path must be a string. Received undefined"

[only-cliches]

Also getting this error, it seems like npx isn't able to scan and find already installed packages.

• Windows 10
• npm 5.5.1
• node 8.9.3

[styfle]

I get the same error on Windows 10.

C:\Users\styfle>node --version
v8.9.4

C:\Users\styfle>npm --version
5.6.0

C:\Users\styfle>npx --version
npx: installed 1 in 2.147s
Path must be a string. Received undefined
9.7.1

[laggingreflex]

Dupe #148

[denishowe]

npx.cmd does
CALL "%NODE_EXE%" "%NPX_CLI_JS%" prefix -g
which is
node c:/nodejs/node_modules/npm/bin/npx-cli.js prefix -g
when it looks like it should be doing
npm prefix -g
Where exactly does npx.cmd come from?

[laggingreflex]

This PR should fix it

[bluelovers]

The "path" argument must be of type string

[oshingc]

I have this issue...

[Sawtaytoes]

@laggingreflex Looks like the PR failed when run through the CI tool.

[colwilson-mo]

Windows 10

node -v
v8.9.4

npm -v
5.6.0

npx -v
npx: installed 1 in 2.458s
Path must be a string. Received undefined
9.7.1

[bertday]

Same issue here.

Windows 7
Node 8.9.4
npm 5.6.0
npx 9.7.1

[Darkle]

I'm getting this as well.

Windows 10
Node v8.10.0
npm 5.7.1
npx 9.7.1

[eybbus]

Same issue here.

Windows 10 64 bit
Node 8.9.4
npm 5.6.0
npx 9.7.1

[sandyarmstrong]

What version will include the fix?

[cekvenich]

Solved in: #168

This issue here #144 should be closed.

[IT0315]

webpack/webpack#2463

[rich-newman]

@cekvenich I don't understand how #168 relates to this. Can you explain please? Are you suggesting that remapping the js file extension will fix this (I've tried remapping it to node.exe and it make no difference to this issue)?

[cekvenich]

Happy to try to help. The reason people all over www get 'Path must be a string' in Windows is because it it not running node, it is running something else.
After windows does some windows update, it breaks things.

So I found that it is not running node as expected. Normally npx does node to run your js.
But sometimes, on windows it runs 'JScript' instead of node.
That is easy to prove, and 168 shows how. The 'path must be a string' error does not come from node.

So now that we know what the exact problem is and we can reproduce it, it should be easier to fix.
Sadly I can't find source code for the npx.cmd.
(also I complained that node org should be doing better testing for windows )

Does that help you @rich-newman ?

[shawwn]

I'm getting this issue on npx 9.7.1, windows 10:

This is confusing for end users, since I want to rely on npx to start my program.

In general, is there a way to get npx to shut up? I'd prefer a mode that doesn't log anything at all, unless there's an error.

[TotallyInformation]

I also added the following to #168 - and I don't believe it is "fixed" by that issue. The issue remains.

---

Given that npx is now distributed with Node.JS, this is a VERY IMPORTANT thing to fix!

I don't pretend to understand all of the technical details but please bear in mind that this - to users - is an npx error, not an npm error. That's because npm works just fine on Windows, npx does not.

I am not trying to be negative. This is a great tool and I want to see it succeed.

[zkat]

This should have been fixed with npm@5.8.0 (if using the bundled npx) and npx@10 (if you're using a standalone npx install). Please don't comment unless you have this bug with one of those versions or later.

[rich-newman]

@zkat Both the 'recommended' LTS version of node (8.11.1) AND the 'current' version (10.0.0) seem to install npm 5.6.0 currently on Windows, and have the problem. So are you saying we just need to wait for the node team to fix this?

[zkat]

@rich-newman pretty much. They'll eventually get around to upgrading the CLI, when they find the time.

In the meantime, though, you can do npm i -g npx to install the standalone version of npx, which should fix this.

[styfle]

npm install -g npm@5.8.0
npm install -g npx@10.0.1

[zkat]

I assume this is fixed since everyone still reporting it is on older versions of npx.

Just upgrade, y'all.

[TotallyInformation]

Thanks for everyone's feedback. However, I would point out that all the excellent suggestions here are workarounds - they are not a solution.

My point is that npx is integrated into Node.JS installations and so that needs to work without user intervention. Applying workarounds often results in long term support issues.

The reason for having an open issue in the npx repo (not just node/npm) is that some users will see this as a problem with npx and should therefore be able to see what the problem is and where the problem comes from.

[FranklinYu]

@TotallyInformation Then the answer is obvious: don't use npx until you are in a Node.js release with fixed version of NPX. Regard this as something you pay for cutting-edge technology; Node.js 8 was simply not yet ready for npx. I would prefer wait until Node.js 10 LTS.

Or if you know some one in Microsoft, tell them that the %PATH% rule is really annoying. That helps everyone, not just Node.js users. It's easy and typical for Linux user to upgrade their global NPM; that shoouldn't be an issue. I believe it's the environment variable rule in Windows that truly annoys most users.

[Darkle]

I wonder if it would be a good idea to have a page on the npm website with some of the info in this issue. There is a page in the getting started section for Linux users about installing npm modules globally here: https://docs.npmjs.com/getting-started/fixing-npm-permissions - although its not exactly the same as the issues in this issue, something similar for Windows might be a good idea.

edit: I just noticed the page now says:

This section does not apply to Microsoft Windows. This chapter will be updated to address Windows in the near future.

so maybe it will be updated with info from here.

[TotallyInformation]

@FranklinYu - I am not using it. Frankly, I didn't even know about it until someone mentioned it on a blog post. But that doesn't help other people who come across the issue does it. If Node wasn't ready for it, that's fine - after all, I'm not paying for it. However, there needs to be clear information.

I do know lots of people at different levels of Microsoft as it happens. But I'm not sure what you are asking? As far as I can see - and maybe I just don't quite get the issue - there is nothing wrong with the default paths. There is simply an issue with the way that npx is configured when it is installed - presumably from the npm installation? Isn't that all that needs fixing?

@Darkle - Yes, that would be a very good idea.

[FranklinYu]

@TotallyInformation

there is nothing wrong with the default paths.

There is something wrong with the default paths. I cannot figure out a reason why user path is appended after system path to form the effective path. In any case I would like the power to override the system path, and that power is available on Linux (not familiar with macOS but I believe it should be similar). It is very useful on Linux and I sometimes write my own "shim" script for some system commands, without administrator privilege. I would say that Windows is not designed with multi-user scenarios in mind.

The only thing NPX can do, is to actively find and execute NPM in user path (so bypassing Windows PATH searching mechanism), and more importantly, make Node.js ship that improved version. Otherwise the globally installed NPX will always be hidden by the one that came with Node.js. I believe NPM itself is already doing this for npm.cmd, because even if I explicitly specify the NPM from Node.js, it still uses the one from my home directory.

[TotallyInformation]

OK, I can see your issue with that. Windows does put system paths first. As I've always used Windows, I guess that is normal to me.

I suspect that the reason for this is security. If you put the user folders first - which are writable by the user of course - then malware could install something with the same name as a file in the system folders.

One of the benefits of using npm is that it adds the local bin folder to the start of the path so that you can run local executables.

I certainly agree that this seems to be an issue that comes from the packaging with npm which itself is packaged with node.js. The actual issue has been fixed, but just needs to be known about until node.js is updated with the fix. I also agree that a test for this should be included in the node and npm packaging tests.

[schontz]

FYI I am running node 8.11.4, npm 6.4.0, and npx 10.2.0 on Windows 10. I was unable to run npx error free until I did what @magnusriga did to fix the path issues. So it seems this is anything but closed.

[FranklinYu]

I suspect that the reason for this is security. If you put the user folders first - which are writable by the user of course - then malware could install something with the same name as a file in the system folders.

@TotallyInformation That is false sense of security. If a user downloaded and run malware, and the antivirus did not stop it, he is already screwed. Nothing can help. Most (if not all) ways to prevent this can be bypassed by malware.

And that is not the design goal of this "system and user separation" (like preventing non-admin from modifying system path). The privilege system is designed to prevent malware from one user to harm other users on the same machine. If I share a Windows machine with my classmate, their malware won't affect me, as long as the administrator is doing the right thing.

[aboutqx]

2 years later still get this...

[FranklinYu]

@aboutqx Read the thread, buddy. It’s already been fixed. Use Node.js 10 if you are in doubt.

[aboutqx]

Ok，i update babel-core,and it works.

[uchikaprojects]

I am still having the same issue with npx

[FranklinYu]

@uchikaprojects Read the thread, buddy. It’s already been fixed. Use Node.js 10 if you are in doubt.

I should make this an auto-reply.

[uchikaprojects]

@FranklinYu Thanks very much, let me check it out

[gangsthub]

Upgrading to Node 10 fixed the issue. Remember to npm ci; as some of your system bindings might fail. 💪

[webworthydesign]

Just in case this helps someone. I had this error and it was being caused by a typo in Grunt. There is a section where we list the themes we want Grunt to rebuild in our project and one of them was spelled wrong. So it was a silly overlook that ended up being a big headache but in the end an easy fix.

A way to find it is to use the --verbose tag when running a grunt build. Hope that helps someone!

[sathyaprakash94]

I had the same issue, I resolved by refering the below documentation.
https://reactjs.org/blog/2016/07/22/create-apps-with-no-configuration.html?utm_source=hashnode.com

[praveens96]

I had the same issue, I resolved by refering the below documentation.
https://reactjs.org/blog/2016/07/22/create-apps-with-no-configuration.html?utm_source=hashnode.com

the link was broken.