Git 3.0's upcoming SHA-256 default will be a costly mistake

The upcoming version of Git 3.0 will default to using SHA-256 as its hash function, which could be a costly mistake due to the increased computational overhead. This change is being made to improve security, but some developers are concerned that it may slow down performance, particularly on older systems. The change is expected to be included in Git 3.0, which is currently in development. The new hash function will be used for all new repositories, but existing repositories will not be affected. The change is being made to take advantage of the increased security provided by SHA-256, which is more resistant to collisions than the current SHA-1 algorithm.