Trouble with Building from g8.1.5 rc1 for Early Version iOS

[Sannyasin Brahmanathaswami]

LC: 8.1.5 rc1
xCode: 8.3.3

I had the lowest version set to iOS 6.1

xCode balked and LC error repor dialog shows up,
saying app build failed because all  these files/libs  (many lines in the SA dialog)  were for 10.3

OK so I went back into SA settings pick "10.3 or later"

and the build went thru

so the question is… how far back, i.e. what is the older version of iOS that *will* work with LC now?

BR