instantbird build failing

[s***@gmail.com]

Hello all,

I am new to this and I cloned the comm-central and mozilla-central repos with mercurial, pulled latest source and everything is up to date, but when I run "mach build" it takes 52 minutes with a build error 2

52:21.12 make[2]: *** [compile] Error 2
52:21.12 make[1]: *** [default] Error 2
52:21.12 make: *** [build] Error 2
52:21.17 1398 compiler warnings present.

How do I know , at which point the build is getting an error ??

Thanks and regards,
Sourabh reddy.