Trezor lock_time error

[sportscliche]

I setup a Trezor hardware wallet and moved my BTC to it.  The balance is correct and Trezor is unlocking the new Electrum wallet.  When I attempt to send BTC from it, I get the following message:

TypeError: sign_tx() got an unexpected keyword argument 'lock_time'

I am on Ubuntu.

[sportscliche]

I removed python-trezor 0.6, downloaded the current version from github and ran

sudo pip install trezor

When I attempt to launch Electrum 2.9.3 or trezorctl, I get the following error

TypeError: __init__() got an unexpected keyword argument 'syntax'

My system is running:
protobuf 3.3.0
libprotoc 2.6.1

I can recover the Electrum GUI by switching back to 0.6, but am unable to move any funds from the hardware wallet.

[sportscliche]

I took a far less systematic approach and hacked around until I got it to work.  The key seemed to be un-installing protobuf and then letting the setup.py routine in python-trezor re-install it. 

I appreciate the guide written here and I'm sure others will find it useful.