For those of you who are anxiously waiting for Ubuntu 10.04 LTS a.k.a Lucid Lynx to release today, might have to wait for some more time. Why? Because a bug in GRUB2 has managed to creep through into the final release of Lucid Lynx. There has been a series of events in last couple of months that succeeded in tampering the feathers in the crown of Lucid Lynx, and this bug is the latest entrant to that list (after the memory leak issue of  X.Org server discovered last week). The Ubuntu team is now busy re-spinning some of the ISOs to remove this bug.

UPDATE :  The bug-fixed ISO has been built and  syncing with the mirrors have started. Sweet!

This GRUB 2 bug (Bug#570765) was discovered earlier this week. Thanks to this bug, the GRUB2 screen fails to show up any other operating system that the system already had prior to installation of Ubuntu 10.04. The GRUB2 screen just gives you just a single option - Ubuntu ( yes... that too with 2.6.32 kernel rather than the newer 2.6.33 ).  Thankfully, the partitions and contents of the hard disk are left untouched and the menu entries for GRUB can be restored using the 'update-grub' command.

Interestingly enough the Ubuntu team decided to address this issue by simply adding a note about it in the Ubuntu 10.04 documentation and asking people to run the 'update-grub' command, if they want to fix this.

So whats next ? Well nothing has been confirmed as of now. But possibilities include going ahead with the release and then issue a patch in a few days - a GRUB2 update, which would rebuild the entries, would be added into the Lucid's repository upon its release. Or even delay the release as indicated by Colin Watson's statement : "Delaying until tomorrow is technically possible, but we'd rather get it out today since that way the folks at the release sprint are all still in London rather than traveling home as scheduled." Also in the planning pipeline is releasing a zero-day Linux kernel update for Ubuntu Lucid, which would automatically address the issue by rebuilding the GRUB entries upon installation of the new kernel.

As of now, folks at Ubuntu have decided to take the safest route of all - re-spinning the ISOs. However, as it would definitely take some time (read days) to re-spin all of the ISOs. They will try to finish off the re-spinning of ISOs of Ubuntu 32 and 64 bit desktop editions along with Ubuntu DVD and Ubuntu 10.04  Netbook Edition and put them up on the mirrors by today. Notifications about re-spining of ISOs have also been issued to folks at Kubuntu, Xubuntu, and the other Ubuntu derivatives.

Heres what is reported on the Ubuntu Wiki :

We had a late discovery of GRUB bootloader bug affecting dual-boot users of Ubuntu. When installing in a dual-boot environment, the other operating system will not appear at first in the GRUB menu. Installing the available updates and rebooting will fix this issue. However, it was determined the day of the release that this is not an optimal solution for new users or those not connected to the Internet.

Also theres a question that might have sprung up in your mind - What if the release date pushes into May? Will Ubuntu Lucid still be called 10.04 or renamed to 10.05 ? Whatever it is, stay tuned for updates and more.