My system-level hgrc file sets debug to on:

hg showconfig|grep ui.debug
/etc/mercurial/hgrc:28: ui.debug=true

This seems to cause problems when parsing the output of hg.

Here's the log output:

13:25:37 Building remotely on myslave in workspace /var/data/jenkins-slave/workspace/MYJOB-2.8.4
13:25:38 $ hg clone --rev 2.8.4 --noupdate http://mymercurialrepo.com.br/hg/main/myjob /var/data/jenkins-slave/workspace/MYJOB-2.8.4
13:25:38 using http://mymercurialrepo.com.br/hg/main/myjob
13:25:38 sending capabilities command
13:25:38 sending lookup command
13:25:38 query 1; heads
13:25:38 sending batch command
13:25:38 sending getbundle command
13:25:38 adding changesets
13:25:38 changesets: 1 chunks
13:25:38 add changeset e1cfb9e9c39a
13:25:38 changesets: 2 chunks
[...]