[build option: install-dir] new `install-dir` not working once installed

Once install folly, specify new install directory with `--install-dir` seems not working. The reason should be the `install_manifest.txt` of `cmake`.

Is it possible to make each new `--install-dir` work? Clean `install_manifest.txt` file before install should work.

My initial intention is buildding folly with bazel, which needs to install folly in each execution.