I don't have any value in the combo above for versions, so I'll give the information here:
the problem appeared between 1.389 (ok) and 1.390 (ko).

With 1.390, the only log I can see seems to come from plugins.
The problem is present with either maven 2 native builds and freestyle jobs (though the result seems a bit different).
The build seems to behave quite normally, since it stays green when it was before, and so on.

With M2 native builds, it seems like the build is triggered in background with the typical line:

<===[HUDSON REMOTING CAPACITY]===>Executing Maven: -B -f /ic/.hudson/jobs/corp-shared-resources/workspace/corp-shared-resources/pom.xml -e -Dsurefire.useFile=false -U clean deploy

And then, without any additional line between, the logs corresponding to surefire report gathering for the hudson plugin is shown:

[HUDSON] Enregistrement des résultats des tests
[HUDSON] Archiving /ic/.hudson/jobs/corp-shared-resources/workspace/corp-shared-resources/pom.xml to /ic/.hudson/jobs/corp-shared-resources/modules/fr.corp$corp-shared-resources/builds

With freestyle jobs, it only shows the execution of external .sh:

[workspace] $ /bin/sh -xe /ic/tmp/hudson64022.sh
[workspace] $ /bin/sh -xe /ic/tmp/hudson64023.sh

The difference is that in this case, the build fails w/ 1.390 and successes w/ 1.389.

Sorry for being so vague.
If you need more information, please let me know.
If I find time, I'll try to have a look at the commit differences between 389 and 390.

PS : I have quite a lot of plugins activated, so I guess it could also be related to that.
PS2: Sorry, I had a hard time choosing the right component. I'm quite sure I didn't .
Cheers