To any other Mac users who run into problems installing taps that need

ciso8601

library, I found this article that suggested I run `xcode-select --install`:

The fix, luckily, is pretty straight forward. Install the Xcode toolkit! Even if you had it installed before, you might have to re-register it or update it to the latest version.

I'm happy to report that following those instructions did the trick allowed me to install the

ciso8601

library and the tap (

tap-spreadsheets-anywhere

)- when previously it had been failing. Hope this helps!