Modify qemu

[AAndrisa]

PR Description

Remove qemu package and install qemu-user-static

PR Type

• Bug fix (a change that fixes an issue)
• New feature (a change that adds new functionality)
• Breaking change (a change that affects other repos or cause CIs to fail)

PR Checklist

• I have conducted a self-review of my own code changes
• I have commented new code, particulary complex or unclear areas
• I have checked that I did not intoduced new warnings or errors (CI output)
• I have checked that components that use libiio did not get broken
• I have updated the documentation accordingly (GitHub Pages, READMEs, etc)

[rgetz]

I'm assuming this isn't done - since it still has build failures on ARM? (that's what is suppost to be fixed?)

[dNechita]

I'm assuming this isn't done - since it still has build failures on ARM? (that's what is suppost to be fixed?)

There are currently 2 issues affecting the ARM builds:

1. QEMU no longer can be installed via apt by using name "qemu" and now it needs to be "qemu-user-static". This was causing all 5 ARM jobs to fail.
2. The GNU toolchain always crashes while building libiio for arm architecture ubuntu-ppc64le and crashes once in a while for other ARM architectures.

This PR addresses the 1st issue.
We've been looking for the cause and for a fix on the 2nd issue but if we don't find them soon, this PR needs to be merged and then we will have 3-4 (out of 5) ARM jobs passing.

[rgetz]

2. The GNU toolchain always crashes while building libiio for arm architecture ubuntu-ppc64le and crashes once in a while for other ARM architectures.

Is this on specific versions of gcc? for now - you should be able to go back a version to unblock things...

sudo apt-cache search ^gcc-9-
sudo apt-git install ...(whatever packages you need)

and report a problem/bug in gcc - https://gcc.gnu.org/bugs/

[dNechita]

2. The GNU toolchain always crashes while building libiio for arm architecture ubuntu-ppc64le and crashes once in a while for other ARM architectures.

Is this on specific versions of gcc? for now - you should be able to go back a version to unblock things...

sudo apt-cache search ^gcc-9-
sudo apt-git install ...(whatever packages you need)

and report a problem/bug in gcc - https://gcc.gnu.org/bugs/

I have already tried with multiple of gcc versions and all have failed.
I have forced the build to use just one core and even forced the docker container to use 4GB of RAM but didn't work.
I have manually built lastest qemu from source but didn't work.

In the end, it worked by disabling Address Space Layout Randomization (ASLR) based on a discussion on this bug report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1087822

[rgetz]

Ok - thanks for the pointer - so it's not a gcc issue - its a qemu/host kernel issue. That helps.