Laravel Mix on Docker: ETXTBSY: text file is busy

I am trying to run Laravel Mix on my Docker container.

I have managed to install the latest versions of npm and node (thanks Laradock).

Now when I try and run npm install I get lots of these:

npm WARN rollback Rolling back [email protected] failed (this is probably harmless): ETXTBSY: text file is busy, unlink '/srv/app/node_modules/express/package.json.3619593601'
npm WARN rollback Rolling back [email protected] failed (this is probably harmless): ETXTBSY: text file is busy, unlink '/srv/app/node_modules/express/node_modules/array-fla
tten/package.json.2934324270'

node:v10.5.0

npm:v6.1.0

Windows host.

Guest is: Linux 2369f4b16e52 4.9.93-boot2docker #1 SMP Thu May 10 16:27:54 UTC 2018 x86_64 GNU/Linux

Is anyone else doing this?

Mick