Since crystal gets to “fix” warts from Ruby…would it be palatable to have the caller method return real objects instead of the “overloaded colon delimited strings” as ruby does? 
Today:
$ crystal eval "pp caller"
["/eval:1:1 in '__crystal_main'",
"/usr/local/Cellar/crystal/0.33.0/src/crystal/main.cr:106:5 in 'main_user_code'",
"/usr/local/Cellar/crystal/0.33.0/src/crystal/main.cr:92:7 in 'main'",
"/usr/local/Cellar/crystal/0.33.0/src/crystal/main.cr:115:3 in 'main'"]