bug#43344: "basic" system tests fail (and all the other ones) on guix master

[Leo Famulari]

On Wed, Sep 16, 2020 at 09:36:49PM -0400, Mark H Weaver wrote:
> > On Wed, Sep 16, 2020 at 04:52:45PM +0200, Danny Milosavljevic wrote:
> >> commit 692d0626557451c4b557397f20b7394b612d0289
> >> Author: Christoph Hellwig <hch@lst.de>
> >> Date:   Tue Sep 1 11:59:41 2020 +0200
> >> 
> >>     block: fix locking in bdev_del_partition

> Next, it probably makes sense to test 5.8.9 with the above commit
> reverted.  Would someone like to try it?  If that works, we can avoid
> the bisection, resume kernel updates, and revert this change across all
> of our kernels until a better solution is found.

Using linux-libre 5.8.9 with that commit reverted, `guix system vm` does
work again.