SlackBuildsOrg/libraries/libsidplay2

Sidplay 2 is capable of playing all C64 mono/stereo file formats and
is cycle accurate for improved sound reproduction.

Build includes the reSID emulation/filter and HardSID support.

For instance, you can use the stock Audacious plugin SlackBuild without
modifications and rebuilding the package.  It will automatically detect
the SID emulation availability and compiles the SID plugin.
Simply reinstall the created package by `upgradepkg --reinstall`.