Firefox's build system is complex, but things are gradually getting easier for newbies. For example, if you're on Linux or Mac there's now a script (see https://developer.mozilla.org/en-US/docs/Simple_Firefox_buil...) that installs all the required dependencies. And |mach|, the (relatively) new build driver program helps. And better build defaults means you can get away without using a mozconfig file, at least to begin with.
As for the build error, I understand that's frustrating. Asking on the #introduction channel on IRC would be a good way to make progress (https://wiki.mozilla.org/IRC). That's a channel with lots of informed people and they're generally very friendly.
In fact, the very first time I built Firefox I had various build problems, and the people on Mozilla's IRC channels quickly helped me identify that it was actually faulty RAM -- I was building on a brand new machine -- at fault!
As for the build error, I understand that's frustrating. Asking on the #introduction channel on IRC would be a good way to make progress (https://wiki.mozilla.org/IRC). That's a channel with lots of informed people and they're generally very friendly.
In fact, the very first time I built Firefox I had various build problems, and the people on Mozilla's IRC channels quickly helped me identify that it was actually faulty RAM -- I was building on a brand new machine -- at fault!