I'm working on updating linux-libre to 5.10.

Using the attached patch, I tried building an ephemeral VM for x86_64:

------
$ guix environment guix -- ./pre-inst-env guix system vm doc/os-config-bare-bones.texi
[...]
building /gnu/store/678f40zf8dpp4w63j8419zad6d7bi32a-linux-modules.drv...
Backtrace:
In srfi/srfi-1.scm:
   586:29 19 (map1 _)
   586:29 18 (map1 _)
   586:29 17 (map1 _)
   586:29 16 (map1 _)
   586:29 15 (map1 _)
   586:29 14 (map1 _)
   586:29 13 (map1 _)
   586:29 12 (map1 _)
   586:29 11 (map1 _)
   586:29 10 (map1 _)
   586:29  9 (map1 _)
   586:29  8 (map1 _)
   586:29  7 (map1 _)
   586:29  6 (map1 _)
   586:29  5 (map1 _)
   586:29  4 (map1 _)
   586:29  3 (map1 _)
   586:29  2 (map1 _)
   586:17  1 (map1 ("virtio_console" "virtio-rng" "btrfs"))
In gnu/build/linux-modules.scm:
    257:5  0 (find-module-file _ _)

gnu/build/linux-modules.scm:257:5: In procedure find-module-file:
kernel module not found "virtio_console" "/gnu/store/hf3v78bnar6pyby40w4xmqc6sjcz4wvb-linux-5.10/lib/modules"
builder for `/gnu/store/678f40zf8dpp4w63j8419zad6d7bi32a-linux-modules.drv' failed with exit code 1
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Indeed, the virtio_console module is missing. For linux-libre 5.9, it
shows up here within the kernel store item:

'lib/modules/5.9.14/kernel/drivers/char/virtio_console.ko.gz'

The 5.10 kernel configuration has "CONFIG_VIRTIO_CONSOLE=y", as before.

Any ideas? I'm trying to build now with "CONFIG_VIRTIO_CONSOLE=m",
although I don't really know why "CONFIG_VIRTIO_CONSOLE=y" was creating
a module file previously.