[$] Git archive generation meets Hyrum's law

On January 30, the GitHub blog carried abrief notice that the checksums of archives (such as tarballs)generated by the site had just changed. GitHub's engineers were seeminglyunaware of the consequences of such a change - consequences that wereimmediately evident to anybody familiar with either packaging systems or Hyrum's law. Those checksums werewidely depended on by build systems, which immediately broke when thechange went live; the resulting impact ofjawbones hitting the floor was observed by seismographs worldwide. Thechange has been reverted for now, but it is worth looking at how GitHubmanaged to casually break vast numbers of build systems - and why this sortof change will almost certainly happen again.