Comment 11 for bug 1602680

Thanks, Sander. That allowed me to figure out the problem.

The new libnspr4 added a new exported function, PR_GetEnvSecure():

  $ nm -D /usr/lib/x86_64-linux-gnu/libnspr4.so | grep PR_GetEnvSecure
  000000000001a3a0 T PR_GetEnvSecure

The new libnss3 depends on that new function:

  $ nm -D /usr/lib/x86_64-linux-gnu/libnssutil3.so.1d | grep GetEnvSecure
                   U PR_GetEnvSecure

If you upgrade libnspr4 to the versions specified in this USN, you won't experience this bug any longer:

  http://www.ubuntu.com/usn/usn-3028-1/

I'm not sure how you kept the old libnspr4 but it looks like the new libnss3 correctly depends on the new libnspr4:

  $ apt-cache show libnss3=2:3.23-0ubuntu0.12.04.1 | grep ^Depends:
  Depends: libc6 (>= 2.4), libnspr4 (>= 4.12), libsqlite3-0 (>= 3.5.9), zlib1g (>= 1:1.1.4)