Similar to Bug 12073, selftest.signing.Signing was failing at setUpClass, error logs are attached below: 

ERROR [0.000s]: setUpClass (oeqa.selftest.signing.Signing)
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Traceback (most recent call last):
  File "/home/ab/autobuilder/yocto-worker/nightly-oe-selftest-ubuntu1710/build/meta/lib/oeqa/selftest/signing.py", line 29, in setUpClass
    runCmd('gpg --homedir %s --import %s %s' % (cls.gpg_dir, cls.pub_key_path, cls.secret_key_path))
  File "/home/ab/autobuilder/yocto-worker/nightly-oe-selftest-ubuntu1710/build/meta/lib/oeqa/utils/commands.py", line 114, in runCmd
    raise AssertionError("Command '%s' returned non-zero exit status %d:\n%s" % (command, result.status, result.output))
AssertionError: Command 'gpg --homedir /tmp/oeqa-signing-_dt2aj9n --import /home/ab/autobuilder/yocto-worker/nightly-oe-selftest-ubuntu1710/build/meta-selftest/files/signing/key.pub /home/ab/autobuilder/yocto-worker/nightly-oe-selftest-ubuntu1710/build/meta-selftest/files/signing/key.secret' returned non-zero exit status 2:
gpg: keybox '/tmp/oeqa-signing-_dt2aj9n/pubring.kbx' created
gpg: /tmp/oeqa-signing-_dt2aj9n/trustdb.gpg: trustdb created
gpg: key 7B31316B5D64AD52: public key "testuser (nocomment) <testuser@testemail.com>" imported
gpg: key 7B31316B5D64AD52: "testuser (nocomment) <testuser@testemail.com>" not changed
gpg: key 7B31316B5D64AD52/7B31316B5D64AD52: error sending to agent: Timeout
gpg: error building skey array: Timeout
gpg: Total number processed: 2
gpg:               imported: 1
gpg:              unchanged: 1
gpg:       secret keys read: 1