regex detection

[birdspider]

js-source

var a = 3
  / 4;

results in

Uncaught RuntimeException: Unclosed regex pattern at position: 
Stack trace:
#0 jshrink.php(298): JShrink\Minifier->saveRegex()
#1 jshrink.php(162): JShrink\Minifier->loop()
#2 jshrink.php(137): JShrink\Minifier->minifyToString(' var x = 3 \n / ...', Array)
#3 JShrink\Minifier::minify(' var x = 3 \n / ...', Array)

#124 does not help in this case