test-build has issues with access rights for folders

[levino]

I run

./test-tools/test-build.sh /home/levin/coding/myrepo 'npm run bootstrap && cd packages/web-app && npm run build'

and get

Installing dependencies
Attempting node version 'v8' from .nvmrc
Downloading and installing node v8.11.3...
Downloading https://nodejs.org/dist/v8.11.3/node-v8.11.3-linux-x64.tar.xz...
######################################################################## 100.0%
Computing checksum with sha256sum
Checksums matched!
Now using node v8.11.3 (npm v5.6.0)
Attempting ruby version 2.3.6, read from environment
Using ruby version 2.3.6
Using PHP version 5.6
Started restoring cached node modules
mv: cannot create directory ‘/opt/buildhome/repo/node_modules’: Permission denied
Finished restoring cached node modules
Installing NPM modules using NPM version 5.6.0
npm WARN checkPermissions Missing write access to /opt/buildhome/repo
npm WARN repo No description
npm WARN repo No repository field.
npm WARN repo No license field.

npm ERR! path /opt/buildhome/repo
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
npm ERR! Error: EACCES: permission denied, access '/opt/buildhome/repo'
npm ERR!  { Error: EACCES: permission denied, access '/opt/buildhome/repo'
npm ERR!   stack: 'Error: EACCES: permission denied, access \'/opt/buildhome/repo\'',
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path: '/opt/buildhome/repo' }
npm ERR! 
npm ERR! Please try running this command again as root/Administrator.

npm ERR! A complete log of this run can be found in:
npm ERR!     /opt/buildhome/.npm/_logs/2018-06-22T08_52_31_236Z-debug.log
Error during NPM install

Do I have to run the install command beforehand? What is happening?