Adding -p to the mkdir command makes it so the error is no longer an issue.
What I was seeing:
...
ok 127 Prints nodenv version when nodenv is installed
mkdir: /tmp/tmp-spacefish/node_modules: File exists
ok 127 Prints nothing when using the "system" version of node with nvm
...
Adding -p to the mkdir command makes it so the error is no longer an issue.
What I was seeing: