Tested on Unraid 6.12

---

1. Install LXC the plugin, create a Slackware 15.0, start and attach to it

2. Upgrade security patches (press O to override when asked)
```
slackpkg upgrade-all
```
3. Get the source from -current branch. I use `rsync`
```
slackpkg install rsync lz4 xxHash
rsync -rzvh rsync://ftp.slackware.com/slackware/slackware-current/source/d/python3/ ~/python3-src
```
3.1. (Optional) You can grab Python3.12 source if you want that version. It works too
```
wget -P ~/python3-src \
  https://www.python.org/ftp/python/3.12.5/Python-3.12.5.tar.xz \
  https://www.python.org/ftp/python/3.12.5/Python-3.12.5.tar.xz.asc \
  https://www.python.org/ftp/python/doc/3.12.5/python-3.12.5-docs-text.tar.bz2
```
4. Static link the `expat` dependency (since its not include on Unraid, it is good to us)
```
sed -i 's/with-system-expat/without-system-expat/' ~/python3-src/python3.SlackBuild
```
5. Include `ensurepip` (optional, I prefer to not)
```
sed -i 's/without-ensurepip/with-ensurepip/' ~/python3-src/python3.SlackBuild
```
5.1. (Optional) If you choose to __not include__ `ensurepip` you can add those lines to `/boot/config/go`
```
# if it has pypthon then upgrade/install pip
[[ -f /usr/bin/python3 ]] && /usr/bin/python3 -m ensurepip --upgrade
```
6. Install dependencies
```
slackpkg install kernel-headers binutils gcc-11 gc-8 make pkg-config guile flex libffi expat zlib gdbm readline
```
7. Build
```
sh ~/python3-src/python3.SlackBuild
```
8. It should go to `/tmp/python3-*.txz` (something like that) inside the container.

9. On the  Unraid LXC plugin Settings (`/Settings/LXCSettings`) get the "storage path", there will be rootfs for your Slackware container, go `tmp` folder. 

10. You know the rest.