It would be ideal if there were a way to wait for a long-running process to finish before the tape continues. For example:
Output demo.gif
Set FontSize 12
Set Width 800
Set Height 500
Type "clojure -T:build test"
Enter
WaitForProcessTermination
Sleep 5s
Note that WaitForProcessTermination is just a placeholder - I'm sure the vhs team have a much better idea of an appropriate command name.