mksquashfs call failed: libgcc_s.so.1 must be installed for pthread_cancel to work

[Heinrich Schuchardt]

Building a snap for core22 on riscv64 fails:

$ snapcraft --use-lxd
Launching instance...
Executed: pull gnu-hello
Executed: overlay gnu-hello
Executed: build gnu-hello
Executed: stage gnu-hello
Executed: prime gnu-hello
Executed parts lifecycle
Generated snap metadata
Cannot pack snap file: Command '['snap', 'pack', '--filename', 'hello_2.12_riscv64.snap', '--compression', 'xz', PosixPath('/root/prime'), PosixPath('/root/project')]' returned non-zero exit status 20. (error: cannot pack "/root/prime": mksquashfs call failed: libgcc_s.so.1 must be installed for pthread_cancel to work)
Failed to execute pack in instance.
Full execution log: '/home/zfsdt/.cache/snapcraft/log/snapcraft-20221128-200603.372254.log'

The installed verison of snapcraft is:
latest/stable: 7.2.8 2022-11-18

File /usr/lib/riscv64-linux-gnu/libgcc_s.so.1 is available on the system.

[Heinrich Schuchardt (xypron)]

When building for core20 I don't see the error.

[Heinrich Schuchardt (xypron)]

To reproduce the problem

git clone https://github.com/ubuntu-core/hello-snapcraftio.git
cd hello-snapcarftio
# replace core20 by core22 in snap/snapcraft.yaml
snapcraft --use-lxd

[William Wilson (jawn-smith)]

I'm seeing this error as well when trying to build the ubuntu-image snap on RISC-V.