ERROR in ngcc is already running at process with id xxxx

Question

When I try to run ng serve command in my project it produce the below error.

ERROR in ngcc is already running at process with id xxxx

Stop the serve and delete this file `node_modules/@angular/compiler-cli/ngcc/ngcc_lock_file` — Jacopo Sciampi, Mar 06 '20 at 08:52
I had this issue too the first time I served an angular 9 application. Or better, I stopped the serve in a "not standard way". — Jacopo Sciampi, Mar 06 '20 at 09:09
File was named `__ngcc_lock_file__` for me. Removing it resolved the problem here too. — rlv-dan, Mar 10 '20 at 12:52
I started getting this same error when I added a library to my workspace. Our custom build script run "ng build" in parallel and reported the error when building in parallel the two applications that use the new library. The fix for me was to enable Ivy in the the new library's tsconfig file. My guess is that the library is built using Ivy and then ngcc isn't needed when building the applications. — Steve Meierhofer, Jan 08 '21 at 15:52
delete nodes_modules and re-run npm install, that was the issue in my case. — Amir Dora., Feb 06 '23 at 18:56

score 211 · Accepted Answer · edited Dec 22 '22 at 09:55

211

Try deleting your ngcc_lock_file in the path:

node_modules/@angular/compiler-cli/ngcc/ngcc_lock_file

Or for Angular 9, the lock file to delete is:

node_modules/@angular/compiler-cli/ngcc/__ngcc_lock_file__

I had the same issue and I and deleted that file and it started working for me.

edited Dec 22 '22 at 09:55

starball

answered Mar 15 '20 at 17:25

Compiler v2

25

In Angular 9, the file name is - `__ngcc_lock_file__` – Akshay Apr 08 '20 at 03:39
@Akshay It doesn't make much of a difference since it is the only file in that location. It is understandable which file it is. – Compiler v2 Apr 08 '20 at 15:33
Thanks, I stopped a build very fast and then this happened, deleting this file did the trick – Mark Aug 10 '20 at 12:57
Helped me two times angular 9 and 10. the answer by rodhan should have the green check :) – Ian Poston Framer Jan 13 '21 at 08:05
this fixed the issue for me while compiling the angular material components – m.yuki Feb 24 '21 at 14:02
My issue is if I have vscode running and try to do a npm build – Manny Jun 29 '21 at 14:34
Alas, it does not always help: sometimes the .lock file is recreated once deleted. Even though nothing is running besides the current build! Seems like ngcc has got some bug lately. – Alexander Jul 24 '22 at 11:29

score 54 · Answer 2 · answered Mar 27 '20 at 07:19

54

 rm node_modules/@angular/compiler-cli/ngcc/__ngcc_lock_file__

answered Mar 27 '20 at 07:19

Ole

that's repeatedly answered, but it's smart. thanks to make it easier. – Aras Jan 23 '21 at 11:11

score 16 · Answer 3 · answered Mar 17 '20 at 10:16

16

Working Solution

Delete all node modules
Close any working terminal or you can shut down your PC if you cant make sure that you've closed all working terminals
run npm i to setup your modules
run ng s

It's working with me well !

answered Mar 17 '20 at 10:16

Omar Hasan

This worked for me. I tried deleting __ngcc_lock_file__, but I had other issues after removing the lock file. – Brandon Rader Apr 03 '20 at 19:53
What is this issues – Omar Hasan Apr 04 '20 at 07:52
Sass compile issues. My Sass files hadn’t changed since last successful compile, so I figured it had to be some hosed node_modules. This turned out to fix it and would’ve fixed the lock issue as well had I not already removed it. – Brandon Rader Apr 05 '20 at 14:22
In my case the ngcc_lock_file was not there, running `npm i` fixed the issue (even when I had run `npm ci` earlier) – Mauricio Gracia Gutierrez Jan 03 '22 at 13:38
@MauricioGraciaGutierrez what system were you using? I see that it dependsd on the version of Angular and potentially a OS as well. In my case the file has a path: node_modules/.ngcc_lock_file – Yevhenii Herasymchuk Jan 08 '23 at 18:58
I was using windows 10 with vscode – Mauricio Gracia Gutierrez Jan 10 '23 at 03:33

score 6 · Answer 4 · answered Mar 06 '20 at 08:28

6

The problem is most-likely a unique case.

Post a full log, so it is possible to troubleshoot your problem.

answered Mar 06 '20 at 08:28

0leg

1

@Oleg, It seems to me there is some issue with the ngcc logic. – Malik Haseeb Mar 06 '20 at 08:33
If you are using Angular 9, is had 14 release candidates (the most tested Angular version up to date). If you are not using some very unique setup - it should have been tested by devs already. Post your config or the full log. – 0leg Mar 06 '20 at 08:46
@malik-haseeb indeed - on my observation, ngcc 13 has more issues with this than versions before! – Alexander Jul 24 '22 at 11:32

4 Answers4