Local macros/tempvars are not automatically dropped

[anddis]

Local macros continue to exist after the end of the do-file. (macOS 10.12.6 - Stata MP 14.2 - ST3)

For example: after executing this code

clear all
macro drop _all
set obs 5
tempvar a 
gen `a' = runiform()
su `a'

the temporary variable a is left in the dataset.