Wrong or non-portable path to 'env'

[Zash]

The opeth executable as installed by luarocks has #!/bin/env moon as shebang. On my Debian 9 system, the path to env is /usr/bin/env.

[Nymphium]

The path where some distros points to env is /usr/bin and others point to is/bin. So I'm ambivalent about either #!/usr/bin/env or #!/bin/env.

Are there any ideas?