Problems with first test site using Civicrm buildkit
Accessing URL http://localhost:7979 requires at least these things:


Your client is able to resolve host localhost to the local IP address
You have a server which is listening to port 7979
Your server on port 7979 is able to listen to that port (not firewalled / filtered)


Check DNS for localhost

If the command host localhost does not resolve to 127.0.0.1, you should check your /etc/hosts file has an entry which defines the correct IP for localhost.

Expected output is something like:

chris@strike:~$ host localhost
localhost has address 127.0.0.1
localhost has IPv6 address ::1


Check server is listening on expected port

From the debug output above, we can see your server expects to bind to port 7979. So we can use lsof to confirm that the expected process is listening on this port.

chris@strike:~ $ sudo lsof -i :7979
COMMAND   PID  USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
nginx     432 chris    6u  IPv4 0x74beb77a214bedc1      0t0  TCP *:micromuse-ncps (LISTEN)
nginx   12446 chris    6u  IPv4 0x74beb77a214bedc1      0t0  TCP *:micromuse-ncps (LISTEN)
nginx   12447 chris    6u  IPv4 0x74beb77a214bedc1      0t0  TCP *:micromuse-ncps (LISTEN)


This output tells us that port 7979 "belongs" to a service named "micromuse-ncps", but we'll ignore that; we're using that port for your AMP hosts. Just read "micromuse-ncps" as saying "7979".

Your output should show that -


The expected program has this port bound. (I'm using nginx, you'll see apache there.)
The expected user account is running this program. (If I saw "alice" instead of "chris" as the username, that might be telling me that Alice's buildkit had already claimed port 7979, so I couldn't have it.)
If no results show up, this might indicate that your webserver didn't know to bind that port, which might happen if the AMP include was not added to the webserver's config file.


Firewalls

If the port is bound but you can't connect to it, that might indicate the presence of a firewall or other system preventing AMP's test connecting.

Documenting firewall configuration isn't in scope here, sorry! Should your buildkit host have a firewall, you'll have to be responsible for making sure that firewall doesn't interfere with buildkit, by ensuring the buildkit/amp ports are available to the expected client IPs.