cljs.main: Sometimes print side effects don't properly occur prior to REPL

Question

Using built 1.10.138:

`
(ns hello-world.core)

(println "Hello world!")
`

Note that sometimes Hello world! is printed, and sometimes only a newline.

`
$ clj -Srepro --main cljs.main --compile hello-world.core --repl
Hello world!
ClojureScript 1.10.138
cljs.user=> :cljs/quit
$ clj -Srepro --main cljs.main --compile hello-world.core --repl

ClojureScript 1.10.138
cljs.user=> :cljs/quit
$ clj -Srepro --main cljs.main --compile hello-world.core --repl
Hello world!
ClojureScript 1.10.138
cljs.user=> :cljs/quit
$ clj -Srepro --main cljs.main --compile hello-world.core --repl
Hello world!
ClojureScript 1.10.138
cljs.user=> :cljs/quit
$ clj -Srepro --main cljs.main --compile hello-world.core --repl
Hello world!
ClojureScript 1.10.138
cljs.user=> :cljs/quit
$ clj -Srepro --main cljs.main --compile hello-world.core --repl

ClojureScript 1.10.138
cljs.user=> :cljs/quit
`

Answer 1

Reference: https://clojure.atlassian.net/browse/CLJS-2625 (reported by mfikes)