$ su nixbld1 -s /run/current-system/sw/bin/bash                                                            [root@leto:/tmp/nix-build-node-nanopos-0.1.5.drv-1]
WARNING: the per-user profile dir /nix/var/nix/profiles/per-user/root should belong to user id 30001

[nixbld1@leto:/tmp/nix-build-node-nanopos-0.1.5.drv-1]$ source env-vars

[nixbld1@leto:/build]$ cd $src

[nixbld1@leto:/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5]$ npm --offline --nodedir=/nix/store/v67zqk9iijmiray8907v8xhgrwmr1k2z-node-sources --production install
npm WARN checkPermissions Missing write access to /nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5
npm ERR! path /nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
npm ERR! Error: EACCES: permission denied, access '/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5'
npm ERR!  { [Error: EACCES: permission denied, access '/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5']
npm ERR!   stack:
npm ERR!    'Error: EACCES: permission denied, access \'/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5\'',
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path:
npm ERR!    '/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5' }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator (though this is not recommended).

[nixbld1@leto:/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5]$ echo $^C

[nixbld1@leto:/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5]$ ls -l ^C

[nixbld1@leto:/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5]$ touch $out/foo
touch: cannot touch '/nix/store/spv3pkjj5z0m14rpvr0shi1fp5br9sxh-node-nanopos-0.1.5/foo': Read-only file system

[nixbld1@leto:/nix/store/7n6c91ayl8lkvjvn7xbrwc3xxwqwban6-nanopos-4b80bd5]$