Linux kernel creator Linus Torvalds has announced Linux 5.15-rc2, the second release candidate for the next version of the Linux kernel.
Torvalds's weekly Sunday wrap-up marked the progress in the Linux kernel but he has also taken the time to point out the thirtieth anniversary of Linux v0.01, which he uploaded from Helsinki on the evening of September 17, 1991.
It is a notable anniversary because the Linux kernel has several valid 'birthdays', as ZDNet's Steven J. Vaughan-Nichols detailed recently. It could be August 25, 1991 when Torvalds publicly announced Linux 0.01 via a mailing list, or on October 5, 1991, when 0.02 became the first public release of the kernel.
But Torvalds also considered 0.01, which was privately released to a few friends, a legitimate birthday too.
"Now, that 0.01 release was never publicly announced, and I only emailed a handful of people in private about the upload (and I don't have old emails from those days), so there's no real record of that. The only record of the date is in the Linux-0.01 tar-file itself, I suspect," he wrote.
"Alas, the dates in that tar-file are for the last modification dates, not the actual creation of the tar-file, but it does seem to have happened around 7:30pm (Finnish time), so the exact anniversary was technically a couple of hours ago."
He added: "Just thought I'd mention it, since while unannounced, in many ways this is the true 30th anniversary date of the actual code."
As for the 5.15-rc2 release itself, Torvalds said he spent a "fair amount of this week trying to sort out all the odd warnings", referring to -Werror -- a change Torvalds enabled earlier this month as new default behavior for all kernel builds that treated all compiler and configuration "warnings" as "errors" that must be fixed.
As noted by Linux news site Phoronix, it caused problems for some kernel contributors since treating warnings as errors stops the kernel build.
Nick Desaulniers of Google argued that "-Werror is great for preventing new errors from creeping in when a codebase is free of warnings for all configs and all targets and the toolchain is never updated. Unfortunately, none of the above is the case for the Linux kernel at this time."
Torvalds initially resisted disabling -Werror by default but was open to making its behavior dependent on certain expectations. He ended up restricting -Werror to test builds of the kernel.
However, he warned last week: "My "no warnings" policy isn't exactly new, and people shouldn't be shocked when I then say "time to clean up *YOUR* house too"."
"I want to particularly thank Guenter Roeck for his work on tracking where the build failures due to -Werror come from," Torvalds wrote Sunday.
"Is it done? No. But on the whole I'm feeling fairly good about this all, even if it has meant that I've been looking at some really odd and grotty code. Who knew I'd still worry about some odd EISA driver on alpha, after all these years? A slight change of pace ;)," he continued.
Torvalds remains convinced -Werror is for a "good cause" and said it wasn't "too bad" he spent much of the week "looking at reports of odd warnings-turned-errors."
"The most annoying thing is probably the "fix one odd corner case, three others rear their ugly heads". But I remain convinced that it's all for a good cause, and that we really do want to have a clean build even for the crazy odd cases," he explains.
"We'll get there," he wrote.
Linux 5.15 stable should be released around November and includes better support for Microsoft's NTFS file system.