Subject: Re: linux-next: build failure after merge of the block tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 27 Apr 2016 01:18:25 +1000

Hi Nicolas,

On Tue, 26 Apr 2016 10:40:57 -0400 (EDT) Nicolas Pitre <[email-masked]> wrote:
>
> If you can reproduce this build failure, could you try a make mrproper 
> and attempt it again?  I, too, would like to find an explanation and a 
> way to reproduce.

I reset my build tree to commit 9d67df654092 ("Merge remote-tracking
branch 'block/for-next'") and the build failed with:

ERROR: ".local_clock" [drivers/vhost/vhost_net.ko] undefined!
ERROR: ".local_clock" [drivers/misc/cxl/cxl.ko] undefined!

:-(

So I did a "make mrproper" and did the build again.

That built correctly.

Then I reset the tree to commit b087ce990625 ("Merge remote-tracking
branch 'input/next'"), did a "make mrproper", "make ppc64_defconfig",
"make" and that built correctly.  So I fast forwarded back to the block
tree merge and did "make ppc64_defconfig" and "make" and that failed
with:

ERROR: ".blk_queue_write_cache" [drivers/block/virtio_blk.ko] undefined!
ERROR: ".blk_queue_write_cache" [drivers/block/ps3disk.ko] undefined!
ERROR: ".blk_queue_write_cache" [drivers/block/nbd.ko] undefined!

Doing the revert made it build, then doing "reset --hard HEAD^" (i.e.
undoing the revert) also kept the build working.

These builds all have a separate object directory and are powerpc64le
hosted powerpc64be cross builds and use "make -j80".

-- 
Cheers,
Stephen Rothwell