(address . bug-guix@gnu.org)
## description
guix shell --container can only mount subdir in /tmp, and fail for all
other dir:
```
# success mount in all subdir of /tmp
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
# fail for all other dir
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
```
## environment
```
$ uname -a
Linux dev_1 5.18.18 #1 SMP PREEMPT_DYNAMIC 1 x86_64 GNU/Linux
$ guix describe
Generation 9 Oct 22 2022 16:05:50 (current)
guix 85aff4d
repository URL: https://git.savannah.gnu.org/git/guix.git
branch: master
commit: 85aff4de30686359ffb50845eb0930c0a18dc8ba
nonguix 3f00d57
repository URL: https://gitlab.com/nonguix/nonguix
branch: master
commit: 3f00d57adce5d0a185708fd5c7c5ff6f852c2bf7
```
## similar issue: