Comment 11 for bug 614713

Reinstall using OpenSSL:
# USE="-gnutls" emerge --oneshot curl

Reinstall using NSS:
# USE="-gnutls nss" emerge --oneshot curl

If you want your settings to persist, particularly when upgrading curl, you'd write its USE flags to a file:
# echo "net-misc/curl -gnutls nss" >> /etc/portage/package.use
This is for NSS, for OpenSSL you'd obviously omit the nss. If the command fails because package.use is a directory, write to an arbitrarily named file within that directory.

I'm not percieving the test failures as a blocker, and neither do gentoo bzr maintainers. But they are an annoying piece of white noise, as I cannot simply run the complete selftest suite when working on a fix, but will have to either explicitely disable some tests or actually read the results to see if the failures can safely be ignored.