Hi,

I really don't know much about Linux but it looks like the problem I reported has something to do with Debian?

https://unix.stackexchange.com/questions/303213/how-to-enable-user-namespaces-in-the-kernel-for-unprivileged-unshare

Now, I don't use Debian at all (I use Guix System) and do you think this is a Bug in Guix (in that this Debian specific word should never even be mentioned in Guix?)

To summarize this bug again:

The Bug:
The container command no longer works, after the commit 8bc5ca5160db3d82bd5b6b2b7ed80c96f42bd33e.
guix environment -C

Additional Information:
Instead of working as it did until the commit, the command now dies with the following error mesage:
guix environment: error: cannot create container: unprivileged user cannot create user namespaces
guix environment: error: please set /proc/sys/kernel/unprivileged_userns_clone to "1"

The message "please set /proc/sys/kernel/unprivileged_userns_clone to "1",
seems irrelevant to Guix System users as it may only relate to Debian users.
I don't know why this Debian specific message is here in the first place...

Disclaimer :-):
I am assuming this is indeed Debian specific (I tried to install LinuxLinux (the Guix default) but failed - my AMD graphics card won't allow me to even boot, unless I use regular Linux. )

I scanned for the phrase in LinuxLibre source code but there was no mention of it:
~/Downloads$ tar -xf linux-libre-5.9.12-gnu.tar.xz
~/Downloads$ cd linux-5.9.12/
~/Downloads/linux-5.9.12$ rg -i unprivileged_userns_clone

Just FYI: the problem phrase is indeed found in the Debian Kernel Patch:
~/co/debian$ rg -i unprivileged_userns_clone
linux/debian/patches/debian/add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by-default.patch
25:+extern int unprivileged_userns_clone;
27:+#define unprivileged_userns_clone 0
36:+    if ((clone_flags & CLONE_NEWUSER) && !unprivileged_userns_clone)
47:+    if ((unshare_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) {
65:+extern int unprivileged_userns_clone;
77:+            .procname       = "unprivileged_userns_clone",
78:+            .data           = &unprivileged_userns_clone,
96:+int unprivileged_userns_clone;


Cheers,
Yasu




commit 8bc5ca5160db3d82bd5b6b2b7ed80c96f42bd33e
Author: Paul Garlick <pgarlick@tourbillion-technology.com>
Date:   Thu Dec 3 16:00:18 2020 +0000

    linux-container: Correct test for unprivileged user namespace support.

    Fixes <https://bugs.gnu.org/31977>;.
    Reported by Paul Garlick <pgarlick@tourbillion-technology.com>.

    * gnu/build/linux-container.scm (unprivileged-user-namespace-supported?):
    Return #f when the 'userns-file' does not exist.

diff --git a/gnu/build/linux-container.scm b/gnu/build/linux-container.scm
index 4a8bed5a9a..3870b50907 100644
--- a/gnu/build/linux-container.scm
+++ b/gnu/build/linux-container.scm
@@ -44,7 +44,7 @@
   (let ((userns-file "/proc/sys/kernel/unprivileged_userns_clone"))
     (if (file-exists? userns-file)
         (eqv? #\1 (call-with-input-file userns-file read-char))
-        #t)))
+        #f)))


On Sat, 2020-12-05 at 09:20 +0900, yasu wrote:
Hi Pj,

Thank you for you reply (and your wonderful Hacking Guide https://gitlab.com/pjotrp/guix-notes/blob/master/HACKING.org)!

I tried the command and it didn't work...

I use Guix System (not a foreign distribution) as described at the bottom :-)

-Yasu


On Fri, 2020-12-04 at 19:55 +0100, Pjotr Prins wrote:
On Fri, Dec 04, 2020 at 05:32:08PM +0100, zimoun wrote:
Have you tried to do the recommandation?

     please set /proc/sys/kernel/unprivileged_userns_clone to "1"

As root:

echo 1 > /proc/sys/kernel/unprivileged_userns_clone

Yes, it is common on Debian and such.

Pj.


root@guix ~# echo 1 > /proc/sys/kernel/unprivileged_userns_clone
-bash: /proc/sys/kernel/unprivileged_userns_clone: No such file or directory

root@guix ~# guix system describe
Generation 5631 Dec 05 2020 09:09:16 (current)
  file name: /var/guix/profiles/system-5631-link
  canonical file name: /gnu/store/qqzk4kvrhxjcia3hcq3xqrcdi36azzz9-system
  label: GNU with Linux 5.9.12
  bootloader: grub-efi
  root device: label: "my-root"
  kernel: /gnu/store/9a93vpq4aa1c3adiaaa3blwc18r9r7zz-linux-5.9.12/bzImage
  channels:
    guix:
      repository URL: https://git.savannah.gnu.org/git/guix.git
      branch: master
      commit: 86d635b85035086d21c319f31f628761df5c82e5
    nonguix:
      repository URL: https://gitlab.com/nonguix/nonguix
      branch: master
      commit: b08ea529d4d36468b20ef4aff6dc87b3de0eff70
    guix-chromium:
      repository URL: https://gitlab.com/mbakke/guix-chromium.git
      branch: master
      commit: 2de450b92e5f2624d4f964407686934e22239f7b
  configuration file: /gnu/store/hlma107m2004g6qq00ihm190am5mh9z0-configuration.scm