Failed to parse changelogN.xml error when starting pipeline jobs

[Adam Paul]

Hello,

I'm getting the following error pretty frequently (~25% of the time) when starting pipeline jobs on one of our Jenkins servers.  It occurs in the scm step of our pipelines, and I've seen it in all 3 of our pipelines on this server:

Failed to parse /opt/jenkins/inst/jobs/nightly.build/builds/43/changelog1.xml: '<?xml version="1.0" encoding="UTF-8"?> <changesets> '

See stage logs for more detail.

The stage logs do not have any more details - console output for that stage step is:

[nightly.build] $ hg showconfig paths.default
[nightly.build] $ hg pull --rev default
pulling from <masterrepo>
no changes found
[nightly.build] $ hg update --clean --rev default
108 files updated, 0 files merged, 0 files removed, 0 files unresolved
[nightly.build] $ hg log --rev . --template {node}
[nightly.build] $ hg log --rev . --template {rev}
[nightly.build] $ hg log --rev 629ca14eef09b0e09c37627a94ea51c0d5129bfb --template exists\n
exists
[nightly.build] $ hg log --template "<changeset node='{node}' author='{author|xmlescape}' rev='{rev}' date='{date}'><msg>{desc|xmlescape}</msg><added>{file_adds|stringify|xmlescape}</added><deleted>{file_dels|stringify|xmlescape}</deleted><files>{files|stringify|xmlescape}</files><parents>{parents}</parents></changeset>\n" --rev "ancestors('default') and not ancestors(629ca14eef09b0e09c37627a94ea51c0d5129bfb)" --encoding UTF-8 --encodingmode replace
[nightly.build] $ hg log --rev . --template {node} 

[nightly.build] $ hg log --rev . --template {rev}

The contents of the changelog look OK to me:

/export/on-gate/usr/fish $ cat /opt/jenkins/inst/jobs/nightly.build/builds/43/changelog1.xml

<?xml version="1.0" encoding="UTF-8"?>

<changesets>

</changesets>

Jenkins 2.46.2 LTS, Mercurial plugin 1.59, java 1.8.0_131, hg 4.1

Any ideas?  I've never seen this error on any of our other Jenkins instances, and it's killing us on this one.

Thanks!

     Adam

[Adam Paul]

Any thoughts on what this may be or how to debug?

[Adam Paul]

Hihi,

For anyone searching for this later, this is:

https://issues.jenkins-ci.org/browse/JENKINS-43176

and a workaround is to put sleeps of different durations in each branch before the SCM step(s) so the parallel branches are not executing SCM steps at the same time.

Rgds,

     Adam