It’s almost time to replace our main bitbucket.org certificate, so we’re planning to do that at 00:00 UTC on May 6 2016.
Most users shouldn’t notice any difference. However, if you're using Mercurial over HTTPS, then you might see this error message after the new certificate is installed:
abort: certificate for bitbucket.org has unexpected fingerprint 3f:d3:c5:17:23:3c:cd:f5:2d:17:76:06:93:7e:ee:97:42:21:14:aa (check hostfingerprint configuration)
If you do see that error, you'll need to update the host fingerprint for bitbucket.org in your ~/.hgrc or Mercurial.ini configuration file:
[hostfingerprints] bitbucket.org = 3f:d3:c5:17:23:3c:cd:f5:2d:17:76:06:93:7e:ee:97:42:21:14:aa