So with recent Mercurial 1.7 releases HTTPS support was tightened, so you are bound to encounter a warning in the form of: warning: bitbucket.org certificate not verified (check web.cacerts config setting).
Now, http://mercurial.selenic.com/wiki/CACertificates there are details on what to configure for certain operating systems. Given I use FreeBSD, I altered my $HOME/.hgrc as follows:
[web] cacerts = /etc/ssl/cert.pem
For OpenBSD this should be in the same place since release 3.8. But apparently NetBSD does not have such a file in base.