SCM commit message

[uilianries]

Retrieve last commit message (Git and SVN). We can use this feature in CPT (Conan Package Tools).

@tags: svn, slow, git

Changelog: Feature: Get commit message
Docs: conan-io/docs#1175

• Refer to the issue that supports this Pull Request.
• If the issue has missing info, explain the purpose/use case/pain/need that covers this Pull Request.
• I've read the Contributing guide.
• I've followed the PEP8 style guides for Python code.
• I've opened another PR in the Conan docs repo to the develop branch, documenting this one.

^{Note: By default this PR will skip the slower tests and will use a limited set of python versions. Check here how to increase the testing level by writing some tags in the current PR body text.}

[uilianries]

I can't reproduce the error from Jenkins. 🤔

The error is:

======================================================================
ERROR: git_commit_message_test (disabled_revisions.conans.test.unittests.util.tools_test.GitToolTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/source/086f/py27/disabled_revisions/conans/test/unittests/util/tools_test.py", line 1606, in git_commit_message_test
    self.assertIsNone(git.get_commit_message())
  File "/tmp/source/086f/py27/disabled_revisions/conans/client/tools/scm.py", line 189, in get_commit_message
    "Unable to get git commit message from '%s': %s" % (self.folder, str(error)))
ConanException: Unable to get git commit message from '/tmp/tmpcSkUdzconans/path with spaces': Command 'git log -1 --format=%s%n%b' returned non-zero exit status 128

The command used to test:

nosetests conans.test -A "not rest_api" --verbosity=1 --processes=3 --process-timeout=1000 --process-restartworker --with-coverage 

Any idea how to create an environment which I can reproduce the same error?

[jgsogo]

I cannot reproduce it in my machine, but having a look at the code this is my diagnosis:

When the test is calling to git.get_commit_message(), there are no commits in the repo, so according to the implementation these lines should be executed:

            status = self.run("status")
            if "No commits yet" in status:
                return None

Nevertheless, it is failing with Command 'git log -1 --format=%s%n%b', so the previous if-clause is False and the function is not returning, next line gets executed:

message = self.run("log -1 --format=%s%n%b")

and it fails (return non-zero).

⇒  git log -1 --format=%s%n%b
fatal: your current branch 'dev' does not have any commits yet

---

Btw, I'm not sure if we can rely on the No commits yet message (is it localized?), but maybe we can simplify the implementation to something like this:

    def get_commit_message(self):
        self.check_repo()
        try:
            return self.run("log -1 --format=%s%n%b")
        except Exception as error:
            return None

Or do you think that the command could fail for other reasons other than No commits yet?

[uilianries]

@jgsogo thanks for helping! 😄

Or do you think that the command could fail for other reasons other than No commits yet?

No, I just wanted to avoid an ugly error message when trying to retrieve the log when there is no commit there. I'll update this PR to ignore the status step.

[jgsogo]

please, @uilianries , solve the conflicting files.

[lasote]

@uilianries Test failing, looks like a missing import.

[uilianries]

@lasote It's working again! 😄