As can be seen on the snapshots page, building the s08 regression tests fails on Windows (both 32 and 64 bit):
?ASlink-Warning-Couldn't find library 's08.lib'
?ASlink-Warning-Couldn't find library 's08'
The regression tests running the Windows binaries depend on the installer to correctly place all the needed files in the Window environment. So when new backends are created and mature to the point that they are being tested in the daily snapshots, the installer script support/scripts/sdcc.nsi also needs to be updated.
I have updated the script to include s08 and r3ka; we'll see on the next cycle if I did it correctly.
Looks like my second attempt worked. Fixed in revision #7784.