Fixing CF: "Hey, how come ColdFusion debugging output is not showing up in my localhost testing?"
Note: This blog post is from 2018. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.This is a problem that has troubled many CF users for some years (especially as they have moved to later operating systems): they find that ColdFusion debugging output does NOT appear to them when testing using a URL with "localhost" for the domain name but it DOES appear if they use the 127.0.0.1 ip address instead.
TLDR (and update since initial post):
If you can add ::1 to the list of debugging IP addresses in the CF Admin, that should solve this problem. If you cannot, that problem was fixed a few months after I wrote this, in CF2018 update 2 and CF2016 update 8, released in Feb 2019 (and it's no longer a problem on CF2021 and above, of course). For those not yet running those, if you find that adding ::1 just turns into 0:0:0:0:0:0:0:2, read on.
For more on the matter, including why it happened, solving it, etc., read on.
127.0.0.1 localhost
This acts as a local DNS proxy and redirects all requests for "localhost" to 127.0.0.1
This actually solves quite a few other issues with using localhost that have plagued folks for years, not just CF related.
I also tweaked the opening to make it more clear that that's an option (in the "in brief" section--which I added with you in mind, as I know you tend not to like "all the waffle".)
Again, though, "the waffle" is more for the matter of our need (for now) to edit the neo-debug.xml because CF doesn't accept adding the ::1 address for us. That's the real problem I wanted to point out, and how editing that file is a workaround, and the challenges with that.
And as I also noted later in the post, editing the hosts file does not always suit everyone. In the forum thread where this came up (mentioned in my bug report), a poster expressed that editing the hosts file had not worked for him. Again, I alluded to some of the possible challenges with that and decided not to make this a post about that but about the CF issue instead.
Still, again I have tweaked the post a bit based on your comment and I thank you for that.