establishing a connection fails due to "ImportError: cannot import name util"

[Karl-Philipp Richter]

At start the following exception is printed to `stdout`:

    ['un\\"o', 'do``s']
    Traceback (most recent call last):
      File "/usr/lib/mysql-workbench/modules/wb_admin_ssh.py", line 44, in <module>
        import paramiko
      File "/usr/lib/python2.7/dist-packages/paramiko/__init__.py", line 30, in <module>
        from paramiko.transport import SecurityOptions, Transport
      File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 49, in <module>
        from paramiko.dsskey import DSSKey
      File "/usr/lib/python2.7/dist-packages/paramiko/dsskey.py", line 26, in <module>
        from Crypto.PublicKey import DSA
    ImportError: cannot import name DSA
    Warning! Can't use connect with timeout in paramiko None
    Ready.

    Traceback (most recent call last):
      File "/usr/share/mysql-workbench/sshtunnel.py", line 32, in <module>
        import paramiko
      File "/usr/lib/python2.7/dist-packages/paramiko/__init__.py", line 30, in <module>
        from paramiko.transport import SecurityOptions, Transport
      File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 32, in <module>
        from paramiko import util
    ImportError: cannot import name util

When a connection is established a dialog "Cannot Connect to Database Server" is displayed and `** (mysql-workbench-bin:25631): WARNING **: Tunnel manager could not be executed` is logged to `stdout`.

`sudo pip install --upgrade paramiko` and `sudo pip install --upgrade pycrypto` don't help.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: mysql-workbench 6.2.3+dfsg-7build1
Uname: Linux 4.0.0-040000-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Apr 22 13:29:41 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-04-02 (19 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Beta amd64 (20150326)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: mysql-workbench
UpgradeStatus: No upgrade log present (probably fresh install)

[Karl-Philipp Richter (krichter722)]

This error occurs due to an error in the `paramiko` python module depending on an error in the `pycrypto` module. Installation of `pycrypto` with `./autogen.sh && ./configure && python setup.py build && sudo python setup.py install` in source root (git commit 7acba5f3a6ff10f1424c309d0d34d2b713233019) and installation of `paramiko` with `python setup.py build && sudo python setup.py install` in the source root (git commit cfeca480db0116c5c8d95ba1aaa9e5e5e02951ed) fixes the issue.

[Karl-Philipp Richter (krichter722)]

After reboot I get the error message `No handlers could be found for logger "paramiko.transport"` when I try to establish the stored connection which worked before reboot, so the workaround is very likely incomplete.

[Karl-Philipp Richter (krichter722)]

Ok, that was just because of `mysql-workbench` not saving the chosen connection type (switches back to TCP/IP over SSH after restart), so that connection type might not work (and might have worked before my workaround), but TCP/IP connections now work with the workaround.