Update cbuildbot.py to print manifests when we sync.

Update cbuildbot.py to print manifests when we sync.

If cbuildbot.py printed out a manifest when it syncs, it would make it possible
for us to reproduce the build later by looking at what revisions the buildbot
was using. This is useful for debugging.

Change-Id: I186ad01eef0090b6c618cb7ad583085197474018

BUG=chromium-os:7069
TEST=Ran test suite with 3441027 patched in (Sosa's patch that fixes an unrelated issue with the unit tests)

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=70b297a

[sosa, 2010-09-25 21:46:43]

http://codereview.chromium.org/3461028/diff/1/2
File bin/cbuildbot.py (right):

http://codereview.chromium.org/3461028/diff/1/2#newcode73
bin/cbuildbot.py:73: # Output manifest
Period at end of comment .  Also why to stdout rather than a well defined file
or use redirect_stdout?

[davidjames, 2010-09-25 22:43:46]

http://codereview.chromium.org/3461028/diff/1/2
File bin/cbuildbot.py (right):

http://codereview.chromium.org/3461028/diff/1/2#newcode73
bin/cbuildbot.py:73: # Output manifest
On 2010/09/25 21:46:43, sosa wrote:
> Period at end of comment .  Also why to stdout rather than a well defined file
> or use redirect_stdout?

What's redirect_stdout? Is there a difference between using redirect_stdout and
just outputting to stdout?

If we directed output to a file, would said file be accessible from the buildbot
web UI? If so, great, that's exactly what we want.

My understanding is that it isn't easy to make new files accessible from the
buildbot web UI. So outputting to stdout along with build output is next best
thing.

But if it's not terribly hard to write output to a file and make that file
accessible from the web UI, I'd love to do that.

[sosa, 2010-09-26 04:46:40]

LGTM.  I was wondering whether or not this was part of a preceding
check in to say communicating the manifest to another step.  If so,
writing to a file would be  much better method or storing it in memory
for a while and dumping at the end would also be.  Since this is just
to help debug /reproduce builds it's fine.

redirect_stdout modifies RunCommand to return stdout as the return
value rather than the return code.  I suggested it as you want to keep
the manifest in mem for a while if you planned to do something else
with it.  Since that's not the intention of the bug, LGTM :)

On Sat, Sep 25, 2010 at 6:43 PM,  <davidjames@chromium.org> wrote:
>
> http://codereview.chromium.org/3461028/diff/1/2
> File bin/cbuildbot.py (right):
>
> http://codereview.chromium.org/3461028/diff/1/2#newcode73
> bin/cbuildbot.py:73: # Output manifest
> On 2010/09/25 21:46:43, sosa wrote:
>>
>> Period at end of comment .  Also why to stdout rather than a well
>
> defined file
>>
>> or use redirect_stdout?
>
> What's redirect_stdout? Is there a difference between using
> redirect_stdout and just outputting to stdout?
>
> If we directed output to a file, would said file be accessible from the
> buildbot web UI? If so, great, that's exactly what we want.
>
> My understanding is that it isn't easy to make new files accessible from
> the buildbot web UI. So outputting to stdout along with build output is
> next best thing.
>
> But if it's not terribly hard to write output to a file and make that
> file accessible from the web UI, I'd love to do that.
>
> http://codereview.chromium.org/3461028/show
>

[raymes, 2010-09-27 16:22:19]

Thanks!

On 2010/09/26 04:46:40, sosa wrote:
> LGTM.  I was wondering whether or not this was part of a preceding
> check in to say communicating the manifest to another step.  If so,
> writing to a file would be  much better method or storing it in memory
> for a while and dumping at the end would also be.  Since this is just
> to help debug /reproduce builds it's fine.
> 
> redirect_stdout modifies RunCommand to return stdout as the return
> value rather than the return code.  I suggested it as you want to keep
> the manifest in mem for a while if you planned to do something else
> with it.  Since that's not the intention of the bug, LGTM :)
> 
> On Sat, Sep 25, 2010 at 6:43 PM,  <mailto:davidjames@chromium.org> wrote:
> >
> > http://codereview.chromium.org/3461028/diff/1/2
> > File bin/cbuildbot.py (right):
> >
> > http://codereview.chromium.org/3461028/diff/1/2#newcode73
> > bin/cbuildbot.py:73: # Output manifest
> > On 2010/09/25 21:46:43, sosa wrote:
> >>
> >> Period at end of comment . &nbsp;Also why to stdout rather than a well
> >
> > defined file
> >>
> >> or use redirect_stdout?
> >
> > What's redirect_stdout? Is there a difference between using
> > redirect_stdout and just outputting to stdout?
> >
> > If we directed output to a file, would said file be accessible from the
> > buildbot web UI? If so, great, that's exactly what we want.
> >
> > My understanding is that it isn't easy to make new files accessible from
> > the buildbot web UI. So outputting to stdout along with build output is
> > next best thing.
> >
> > But if it's not terribly hard to write output to a file and make that
> > file accessible from the web UI, I'd love to do that.
> >
> > http://codereview.chromium.org/3461028/show
> >
>

[tbourget, 2010-09-27 16:48:38]

would prefer to combine this with the feature to save the pinned deps (bug
5167). for example it would make sense to "repo manifest -o - -r | tee
$pinned_manifest" so it comes to stdout at the same time.

[kliegs, 2010-09-27 17:37:00]

LGTM.

I'm fine with dumping this to stdout as it provides an immediate debugging
aid that is useful to current problems.

The enhancements/future functionality make sense to me but are probably
worth filing as separate bugs/CLs so we make this information available
sooner rather than later.

On Mon, Sep 27, 2010 at 12:48 PM, <tbourget@codeaurora.org> wrote:

> would prefer to combine this with the feature to save the pinned deps (bug
> 5167). for example it would make sense to "repo manifest -o - -r | tee
> $pinned_manifest" so it comes to stdout at the same time.
>
>
> http://codereview.chromium.org/3461028/show
>