Linking error

I had this issue last month …
clang: error: linker command failed with exit code 1 (use -v to see invocation)

not sure how I fixed it, (I think it fixed itself)

my Xcode is 12.0 but I cannot upgrade it as to do so requires first to upgrade OS from Mac Catalina to the newest Big Sur… but, I cannot get that done on this Mac mini with limited space.
But, all factors are the same now (a month later) and although it got corrected somehow last month and I was able to start building iOS apps again; this time it continues to fail

on the simulator ‘build’ menu it shows. iOS sdk: 14.5(UNSUPPORTED local iOS sdk is14.0
which I have in the past (even just yesterday) repeatedly been able to ignore that and still build successfully, choosing ‘YES’ build anyway

anyone experience such linking errors on Mac?


I wish to withdraw this post - matter is covered in another post about iOS unable to build suddenly.