On nuxeo instance, having a contextpath (jenkins/), scm sync popup window doesn't work because rootUrl = https://qa.nuxeo.org/, thus, url to test for config page, for instance, is jenkins/configure : doesn't match the ^configure$ regex.
_Original message :
Most of the time, there is no pop-up window suggesting to fill a commit message. At the end, when the popup window works, the commit message is << Modification on file by jcarsique with following comment : >> even if the user message is empty; whereas when the issue happens, the commit message is << Modification on file by jcarsique >>.
Note there's a "tabulation" character between the two words "following" and "comment" instead of a regular space, and there should be no space before the ending colon ":" (English rule versus French one)._