Re: guix shell: error: mount: Invalid argument

[bbb ee]

/tmp, /, $HOME are in same partition. But only subdir of /tmp are mountable:
```
dev_1@dev_1 /tmp/test2$ df .
Filesystem     1K-blocks      Used Available Use% Mounted on
/dev/nvme0n1p7 209921236 180793652  19663932  91% /
dev_1@dev_1 /tmp/test2$ guix shell --container coreutils -- echo Elmo
Elmo
dev_1@dev_1 /tmp/test2$ cd /tmp/
dev_1@dev_1 /tmp$ df .
Filesystem     1K-blocks      Used Available Use% Mounted on
/dev/nvme0n1p7 209921236 180793720  19663864  91% /
dev_1@dev_1 /tmp$ guix shell --container coreutils -- echo Elmo
Elmo

dev_1@dev_1 /tmp$ cd /
dev_1@dev_1 /$ df .
Filesystem     1K-blocks      Used Available Use% Mounted on
/dev/nvme0n1p7 209921236 180793808  19663776  91% /
dev_1@dev_1 /$ guix shell --container coreutils -- echo Elmo
guix shell: error: mount: mount "/" on "/tmp/guix-directory.fKcwvT//":
Invalid argument

dev_1@dev_1 /mnt/recoverData$ cd ~
dev_1@dev_1 ~$ df .
Filesystem     1K-blocks      Used Available Use% Mounted on
/dev/nvme0n1p7 209921236 180793732  19663852  91% /
dev_1@dev_1 ~$ guix shell --container coreutils -- echo Elmo
guix shell: error: mount: mount "/home/dev_1" on
"/tmp/guix-directory.LUuYdU//home/dev_1": Invalid argument
```

Other partition is also no mountable:
```
dev_1@dev_1 /mnt$ cd recoverData/
dev_1@dev_1 /mnt/recoverData$ df .
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/nvme0n1p8 122503676 91394804  25287412  79% /mnt/recoverData
dev_1@dev_1 /mnt/recoverData$ guix shell --container coreutils -- echo Elmo
guix shell: error: mount: mount "/mnt/recoverData" on
"/tmp/guix-directory.ut68VE//mnt/recoverData": Invalid argument
```

I don't think it is a partition issue.

Le sam. 19 nov. 2022 à 12:47, Tobias Geerinckx-Rice <me@tobias.gr> a écrit :

> Hi bbb,
>
> bbb ee 写道：
> > I feel guix shell --container can only mount subdir in /tmp, and
> > fail for
> > all other dir:
>
> Your example for ‘all other dir’ just tests /home/dev_1 again,
> which looks extremely much like a mount point.  So does /mnt.  So
> no mystery there, but I do wonder what's *special* about these
> mountpoints compared to others.
>
> What is mounted at /home/dev_1 and (presumably) /mnt on your
> system?  Anything mounted at /home?  Anything mounted *below*
> /mnt/*?
>
> On my system:
>
> --8<---------------cut here---------------start------------->8---
> ~ λ mountpoint /tmp
> /tmp is a mountpoint
>
> ~ λ guix shell -C --expose=/tmp=/test coreutils -- echo Elmo world
> Elmo world
>
> ~ λ guix shell -C --expose=/proc=/test coreutils -- echo Elmo
> world
> guix shell: error: mount: mount "/proc" on
> "/tmp/guix-directory.zTa1qb//test": Invalid argument
> --8<---------------cut here---------------end--------------->8---
>
> Weird!  Clearly, /proc is imbued with magical Kernel magick and
> simply canno— what?  Oh:
>
> --8<---------------cut here---------------start------------->8---
> ~ λ mount | grep /proc
> none on /proc type proc (rw,relatime)
> binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc
> (rw,relatime)
> --8<---------------cut here---------------end--------------->8---
>
> Surely not…
>
> --8<---------------cut here---------------start------------->8---
> ~ λ sudo umount /proc/sys/fs/binfmt_misc
>
> ~ λ guix shell -C --expose=/proc=/test coreutils -- echo Elmo
> world
> Elmo world
> --8<---------------cut here---------------end--------------->8---
>
> …huh.
>
> So, ‘guix shell --container’ apparently takes issue with rbind'ing
> mounts, or something like that.
>
> Maybe that's something Guix can handle by bind-mounting the entire
> subtree itself, or maybe it's a hard permissions error enforced by
> the kernel.  I don't know.
>
> Someone with podman/Docker/similar experience might.
>
> Kind regards,
>
> T G-R
>