METEOR_PROFILE does not work on meteor build

[ofpiyush]

Continuing from meteor/meteor#9472

A description of the problem you're trying to solve

Our builds were in the order of 13-17 minutes, this made it very difficult to release faster. We upgraded to meteor 1.6, that lowered the build time but it was still around 8-10 minutes.

We tried to profile the build to see what was going wrong and realised that profiling only covered ProjectContext prepareProjectForBuild step.

First we thought it was a bug, reported to the main repo. @hwillson was kind enough to point out that this feature may have never existed.

Why you think this is a problem

I manually wrapped the buildCommand's invocation to run the profiler and added a few profiling points where I felt they were missing.

This led us to find that tarballing and minification were the biggest offenders.
Two simple changes we made caused our build times to reach under 4 minutes.

• Passing --directory flag and tarballing via linux command
• Disabling minification with the --debug flag (for staging builds)

Without profiling, we'd be shooting in the dark and might hit the issue at random, but with profiling it was clear as day.

Suggested solution

I do not know what a solution would look like, but we changed build function to have
Profile.run("build",()=>{return buildCommand(options)});

We then wrapped several steps inside the buildCommand function to be wrapped with the profiler.

[KoenLav]

@benjamn this is fixed right?

[ofpiyush]

I am no longer using meteor so can't test this. Closing this issue in a mega cleanup of issues I am involved with.