MATLAB: Git push and fetch fail from context menu, but successful from command line

gitMATLABsource control

I have git up and running with SSH authentication to a remote server. I setup git for MATLAB according to this Mathworks Support Team Answer and the integrated git documentation . Push and fetch operations are successful using the !git extension from the MATLAB command line (as well as from system git bash and gui). For example, !git clone git@server:abc/repo successfully clones a local repository. But selecting push or fetch from the Source Control context menu results in the following error:
git@server:abc/repo: Algorithm negotiation fail
I would have guessed that the context menu items and corresponding !git commands were both wrappers to the same system level git syntax. Clearly not, so I am stumped. Has anyone seen this sort of error while using git within MATLAB? Any troubleshooting ideas?
[…Windows 7 64-bit, Msysgit 2.7.2, R2015b…]

Best Answer

Resolved by adding the following to the server-side sshd_config file:
KexAlgorithms diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
Note that the full list, including contemporary defaults, would be:
KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
The UI context menu commands (right click in current folder window, Source Control sub-menu) behave differently from the system level git commands; MATLAB ships with a different version of ssh.
Related Question