Subject: Re: bug#37967: guix environment -CN: Operation not permitted mounting host's /var/run/nscd

From: Ludovic Courtès <[email-masked]>
Date: Fri, 01 Nov 2019 15:26:27 +0100

Ivan Vilata i Balaguer <[email-masked]> skribis:

> Salut Ludovic !

Hola!  :-)

> Ludovic Courtès (2019-10-29 23:16:49 +0100) wrote:
>
>> Bon dia Ivan,
>> 
>> Ivan Vilata i Balaguer <[email-masked]> skribis:
>> 
>> > Hi!  While using Guix commit `c9fc03a3` on Debian unstable, whenever I run
>> > `guix environment -CN` (either as a normal user or as root) I get an error
>> > like this:
>> >
>> >     guix environment: error: mount: mount "/var/run/nscd" on "/tmp/guix-directory.6kBgXe//var/run/nscd": Operation not permitted
>> >
>> > nscd is installed and working in my host machine.
>> 
>> What does ‘uname -rs’ return?
>
>     $ uname -rs
>     Linux 5.2.0-3-amd64
>
>> What about ‘ls -ld /var/run/nscd’?
>
>     $ ls -ld /var/run/nscd
>     drwxr-xr-x 2 root root 60 Oct 29 15:58 /var/run/nscd

Hmm, what does this command return:

  mkdir /tmp/tt
  unshare -mUr mount --bind /var/run/nscd /tmp/tt

?

What about a read-only bind mount like this:

  unshare -mUr mount --bind -o ro /var/run/nscd /tmp/tt

?

What if you try bind-mounting a directory owned by your user?

  mkdir /tmp/mine
  unshare -mUr mount --bind /tmp/mine /tmp/tt

?

Thanks in advance,
Ludo’.