The release of X/OS Linux 4 is delayed to examine a problem with the kernel included in Update 1 (U1).

After several builds in the process to produce the final release image, a potential problem was discovered with the NPTL code in the U1 kernel. The issue is triggered by tests executed during the compilation of glibc. A similar failure of these tests was found in the U1 kernel of other rebuild projects.

Although it's unlikely that this issue will cause problems during normal operation, it was decided to have a closer look before the release. With the final build in sight, the release of X/OS Linux 4 is now expected in about one week.