not able to install MAAS from snap on ppc64le

[Patricia Domingues]

I'm not able to install MAAS from snap on ppc64le machines.
I've Tried with Ubuntu Bionic and Focal:

First, upgrading snapd:
`Unpacking snapd (2.45.1+18.04) over (2.42.1+18.04)`

```
$ sudo snap install maas
error: cannot perform the following tasks:
- Run install hook of "maas" snap if present (run hook "install": /snap/maas/7809/meta/hooks/install: line 61: 22535 Segmentation fault (core dumped) "$SNAP/bin/maas-wrapper" migrate --configure)
```

```
ubuntu@wichita:~$ snap list
Name Version Rev Tracking Publisher Notes
core18 20200427 1752 latest/stable canonical* base
maas-cli 0.6.5 15 latest/stable canonical* -
snapd 2.45.1 8143 latest/stable canonical* snapd
```

trying 2.7:
```
$ sudo snap install maas --channel=2.7/stable
error: cannot perform the following tasks:
- Run install hook of "maas" snap if present (run hook "install": signal: segmentation fault (core dumped))
```

[Taihsiang Ho (tai271828)]

For arm64 platform I have similar (but not sure if it is the same) failure. Please feel free to let me know if it is better to report with another new bug:

```
ubuntu@awrep6:~$ lxc exec maas-snap -- /bin/bash root@maas-snap:~# snap list
Name Version Rev Tracking Publisher Notes
core18 20200427 1753 latest/stable canonical✓ base
lxd 4.2 15727 latest/stable/… canonical✓ -
snapd 2.45.1 8147 latest/stable canonical✓ snapd
root@maas-snap:~# snap install maas
error: cannot perform the following tasks:
- Run install hook of "maas" snap if present (run hook "install": chown: changing ownership of '/var/snap/maas/common/log': Invalid argument)
root@maas-snap:~#
```

[Frank Heimes (fheimes)]

Just as a side note and for the records, I was able to successfully snap install maas on s390x and did not ran into these issues (but so far I only did the snap install, nothing more yet).

[John Lotoski (johnny101)]

For anyone having the same error that @taihsiangho mentions above, one possible cause may be from using LXC/LXD containers and not having an appropriate UID mapping for the snap_daemon user at the default high UID. See the following discourse thread for details:

https://discourse.maas.io/t/unable-to-install-maas-snap-on-lxd/3544

[Alberto Donato (ack)]

Patricia,

is the snap being installed in a container or directly on the host?

[Patricia Domingues (patriciasd)]

that test was directly on a Power8 baremetal, tried again on the same system, now it has 21.04/Hirsute and got the same: ```
ubuntu@wichita:~$ sudo snap install maas

error: cannot perform the following tasks:
- Run install hook of "maas" snap if present (run hook "install": /snap/maas/12544/meta/hooks/install: line 71: 4132823 Segmentation fault (core dumped) "$SNAP/bin/maas-wrapper" migrate --configure)
```

let me know if you need any more tests, I can do.

[Björn Tillenius (bjornt)]

I can reproduce this on our ppc system as well, and I've confirmed that it affects 3.0 as well.

[Alberto Donato (ack)]

The segfault seems to be caused by libsnapcraft-preload.so, which is LD_PRELOAD'd in the bin/ld-preload wrapper script

[Alberto Donato (ack)]

As a simpler reproducer, this segfaults:

sudo snap run --shell maas.supervisor -c 'LD_PRELOAD=$SNAP/lib/libsnapcraft-preload.so cat /etc/hostname'

[Jerzy Husakowski (jhusakowski)]

There seems to be a problem with snapcraft preload. Any ideas? Is it still reproducible?

[Patricia Domingues (patriciasd)]

tried with Focal on a Power9 server `snapd 2.54.4 15180 latest/stable canonical✓ snapd`
and still the same error:

```
$ sudo snap install maas
error: cannot perform the following tasks:
- Run install hook of "maas" snap if present (run hook "install": /snap/maas/18197/meta/hooks/install: line 71: 7774 Segmentation fault (core dumped) "$SNAP/bin/maas-wrapper" migrate --configure)
```

It was going to install MAAS 3.1.0:
`3.1/stable: 3.1.0-10901-g.f1f8f1505 2022-01-19 (18197) 146MB -`

[Jerzy Husakowski (jhusakowski)]

MAAS 3.3 is based on 22.04 and uses an updated toolchain. It would help us if someone could confirm if the issue is reproducible on MAAS 3.3, as we currently don't have access to Power9 machines to test it ourselves.

[Patricia Domingues (patriciasd)]

Trying with --edge channel I can install MAAS on a Power9 (tiselius):

host with Jammy: `Description: Ubuntu 22.04.1 LTS`

` 3.3/edge: 3.3.0~rc1-13134-g.e94f9008d 2022-12-14 (25371)`

~$ sudo snap install maas --channel 3.3/edge
maas (3.3/edge) 3.3.0~rc1-13134-g.e94f9008d from Canonical✓ installed

:~$ snap list |grep maas
maas 3.3.0~rc1-13134-g.e94f9008d 25371 3.3/edge canonical** -
maas-cli 0.6.8 80 latest/stable canonical** -

Thank you.