Build server fails with error can't find python module pyasn1

My build on the snapcraft build servers keeps failing.

The build works if I build the snap on my local host.

I’m however not certain if this the primary error or a secondary one. Either way I guess it needs to be fixed:

setproxy:

trydownload.check:

trydownload:

setproxy:

trydownload.check:

trydownload:

BUILD FAILED
/build/e4039a0b32e4bca67d290294684c86d6-xenial/parts/tomcat/build/build.xml:2623: The following error occurred while executing this line:
/build/e4039a0b32e4bca67d290294684c86d6-xenial/parts/tomcat/build/build.xml:2773: the archive download-1373338744.tar.gz doesn't exist

Total time: 1 second
/usr/lib/python3/dist-packages/ndg/httpsclient/subj_alt_name.py:22: **UserWarning: Error importing pyasn1**, subjectAltName check for SSL peer verification will be disabled.  Import error is: No module named 'pyasn1'
  warnings.warn(import_error_msg)
/usr/lib/python3/dist-packages/ndg/httpsclient/ssl_peer_verification.py:25: UserWarning: SubjectAltName support is disabled - check pyasn1 package installation to enable
  warnings.warn(SUBJ_ALT_NAME_SUPPORT_MSG)
/usr/lib/python3/dist-packages/ndg/httpsclient/subj_alt_name.py:22: UserWarning: Error importing pyasn1, subjectAltName check for SSL peer verification will be disabled.  Import error is: No module named 'pyasn1'
  warnings.warn(import_error_msg)