3.29.0 deletes cache when rerunning cmake -DCMAKE_C_COMPILER=/usr/./bin/cc
LLVM build using cmake fails on macOS (and other platforms): https://github.com/Homebrew/homebrew-core/pull/165206 This issue was analysed by LLVM, and the team concluded to a cmake regression: https://github.com/llvm/llvm-project/issues/86744 They do not appear to have filed a cmake bug, however, so I am creating this.
The issue is in the way cmake treats variable that include ./