Install of nightly with install.sh is not latest version

[Jamie via Digitalmars-d-learn]

When using the install.sh script and choosing 'dmd-nightly' I'm 
currently getting DMD v2.091.0-beta.2-master-ec39fe5 (the folder 
downloaded is dmd-master-2020-03-10).

I can install a more recent version using install 'dmd' etc.
Is this a bug? Or am I just using it incorrectly?

Cheers