Summary
Alpine is a Linux distribution that aims to have a very small footprint compared to other Linux distributions/OSes.
This makes it a prime and popular OS to build Docker images with to make sure containers run as lean and effectively as possible.
The problem comes when a Sauce Connect tunnel is trying to be used with Alpine.
Sauce Connect requires glibc, a library of tools available in most GNU/Linux systems. Alpine is not one of those and requires extra configuration to ensure your Sauce Connect tunnel can be used.
A tell-tale sign of this being an issue is seeing the following error:
qemu-x86_64: Could not open '/lib64/ld-linux-x86-64.so.2': No such file or directory
Solution
There are two main solutions for this issue, both of them revolving around installing glibc on Alpine.
Use Sauce Connect Docker official images
If you want to use Sauce Connect with Alpine on Docker you can simply use/base your image on Sauce Labs' official Alpine SC images.
These can be found here:
https://hub.docker.com/r/saucelabs/sauce-connect
and will be marked with the "-alpine-glibc" suffix.
Install glibc library on Alpine
Alternatively if you are not using Docker or you already have an existing image that you don't want to base off Sauce's, installing glibc tools yourself will also work.
Alpine's documentation shows you how to do this:
https://wiki.alpinelinux.org/wiki/Running_glibc_programs