A bit late to the party, but I just tried #12653 and noticed some non-intuitive behavior (on macOS), that's probably worth explaining release notes and help.

Before this new feature I kept the entire datadir on an SSD drive, so I launch with: `bitcoind -datadir=/Volumes/SSD/Bitcoin`.

Initially I naively moved `/Volumes/SSD/Bitcoin/blocks` to `/Users/bitcoin/blocks` and added a line to `/Volumes/SSD/Bitcoin/bitcoin.conf`: `blocksdir=/Users/bitcoin/blocks`.

I then realized that I shouldn't have moved the `index` subdirectory, so I moved that back to `/Volumes/SSD/Bitcoin/blocks/index`. Having an empty `blocks` dir with just and `index` subdir is a bit weird. Perhaps after @jimpo's #11857 is merged, we could just move / assume all indexes to be there (if `-blocksdir` is set)?

Worse, it created a directory `/Users/bitcoin/blocks/blocks`, which seems like a bug. I had to set `blocksdir=/Users/bitcoin` instead.
{
    
    
    
    if (!LockDataDirectory(false)) {
        
        return false;
    }
    return true;
}
bool AppInitMain()
{
    const CChainParams& chainparams = Params();
    
#ifndef WIN32
    CreatePidFile(GetPidFile(), getpid());
#endif
    if (g_logger->m_print_to_file) {
        if (gArgs.GetBoolArg("-shrinkdebugfile", g_logger->DefaultShrinkDebugFile())) {