Not my fav because I'm not proficient in anything and don't consider myself a programmer. But, I use many languages day to day as a sysadmin.

I come across Perl enough to know I don't like how their modules and dependencies work. I have the most difficulty when dealing with this. PHP, Python, Ruby, and GoLang never give me as much trouble as Perl.

Also, coming across more Python3 dependencies, dealing with older Python2 environments, as stated by many others as well, is becoming more and more painful.

Maybe all of this can be solved with some unifying virtualenv for all popular languages/environments, supported fully by the underlying OS.