[recipe_modules/step] do not set cwd if it is start_dir.

[recipe_modules/step] do not set cwd if it is start_dir.

This makes expectations consistent (i.e. steps that are run without cwd
and steps run in start_dir have the same representation in expectations,
because they have the same behavior).

R=dnj@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2875543002
Committed: https://github.com/luci/recipes-py/commit/c93ed98c3c3e6c9be82e88496e55cb1f3dd13372

[iannucci, 2017-05-10 01:33:55]

The CQ bit was checked by iannucci@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-10 01:33:57]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-10 01:39:07]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-10 01:39:07]

Dry run: Try jobs failed on following builders:
  Recipes-py Presubmit on luci.infra.try (JOB_FAILED,
https://luci-milo.appspot.com/swarming/task/3608d195a6e08d10)

[iannucci, 2017-05-10 01:40:47]

The CQ bit was checked by iannucci@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-10 01:40:56]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[iannucci, 2017-05-10 01:42:28]

PTAL

[iannucci, 2017-05-10 01:46:16]

The CQ bit was checked by iannucci@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-10 01:46:26]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-10 01:49:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-10 01:49:17]

Dry run: This issue passed the CQ dry run.

[nodir, 2017-05-10 01:52:24]

nodir@chromium.org changed reviewers:
+ nodir@chromium.org

[nodir, 2017-05-10 01:52:25]

lgtm

https://codereview.chromium.org/2875543002/diff/10009/recipe_modules/step/exa...
File recipe_modules/step/example.py (right):

https://codereview.chromium.org/2875543002/diff/10009/recipe_modules/step/exa...
recipe_modules/step/example.py:49: api.step('something', ['bash', '-c', 'echo
Why hello, there, in a subdir.'])
Did you mean "Well"?

[iannucci, 2017-05-10 01:56:51]

https://codereview.chromium.org/2875543002/diff/10009/recipe_modules/step/exa...
File recipe_modules/step/example.py (right):

https://codereview.chromium.org/2875543002/diff/10009/recipe_modules/step/exa...
recipe_modules/step/example.py:49: api.step('something', ['bash', '-c', 'echo
Why hello, there, in a subdir.'])
On 2017/05/10 01:52:25, nodir wrote:
> Did you mean "Well"?

Either one works :)
https://english.stackexchange.com/questions/69082/origin-of-why-hello-there

[iannucci, 2017-05-10 01:57:01]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2017-05-10 01:57:07]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-10 01:59:59]

CQ is committing da patch.

Bot data: {"patchset_id": 10009, "attempt_start_ts": 1494381421527110,
"parent_rev": "9f2573a386ee07450095cbeb3562df94a644962f", "commit_rev":
"c93ed98c3c3e6c9be82e88496e55cb1f3dd13372"}

[commit-bot: I haz the power, 2017-05-10 02:00:05]

Description was changed from

==========
[recipe_modules/step] do not set cwd if it is start_dir.

This makes expectations consistent (i.e. steps that are run without cwd
and steps run in start_dir have the same representation in expectations,
because they have the same behavior).

R=dnj@chromium.org
BUG=
==========

to

==========
[recipe_modules/step] do not set cwd if it is start_dir.

This makes expectations consistent (i.e. steps that are run without cwd
and steps run in start_dir have the same representation in expectations,
because they have the same behavior).

R=dnj@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2875543002
Committed:
https://github.com/luci/recipes-py/commit/c93ed98c3c3e6c9be82e88496e55cb1f3dd...
==========

[commit-bot: I haz the power, 2017-05-10 02:00:06]

Committed patchset #3 (id:10009) as
https://github.com/luci/recipes-py/commit/c93ed98c3c3e6c9be82e88496e55cb1f3dd...

[nodir, 2017-05-17 17:37:10]

On 2017/05/10 02:00:06, commit-bot: I haz the power wrote:
> Committed patchset #3 (id:10009) as
>
https://github.com/luci/recipes-py/commit/c93ed98c3c3e6c9be82e88496e55cb1f3dd...

I suspect this CL is incorrect. It removes cwd=start_dir logic, but does not add
in another place. Code search confirms that
https://cs.chromium.org/search/?q=_STEP_CONTEXT+package:%5Echromium$&type=cs
There are places in code that use os.getcwd() when cwd==None, assuming
_STEP_CONTEXT.start_dir == os.getcwd() and assuming that os.getcwd() will not
fail (it fails if cwd does not exist anymore).

this CL seems to be at least complicating debugging of p0 crbug.com/721466
and triggering exception in
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Ftryserver.chromium.linux...

can we revert it to resolve p0? (assuming it would help) and then reland it
without the aforementioned bug?

[nodir, 2017-05-17 17:38:40]

A revert of this CL (patchset #3 id:10009) has been created in
https://codereview.chromium.org/2886903004/ by nodir@chromium.org.

The reason for reverting is: see comment 20.