The implementation of triple-quoted strings, EEP 64, has been merged to ‘master’ to be released in OTP-27.0 and all pre-releases. Since it is allowed today to concatenate a regular string with an empty string which looks like a triple-quoted string, the misfeature adjacent strings without intervening white space, will become a syntax error in OTP-27.0.
In preparation, a fix has been merged to ‘maint’ to be released in OTP-26.2, which produces a compile time warning for the same syntax weirdness.