Canonical multipass, which is in turn used by ubuntu snapcraft may crash unless ~/.ssh/config is moved away. This seems to be due to two issues. One of them is in multipass, that lets libssh parse ~/.ssh/config when there is no reason to do so. The second one seems to be in libssh itself that ends up crashing on pieces of configuration in ~/.ssh/config that it does not understand.
For instance, proxyjump entries or pointers to keys that do not exist seem to be enough to cause the crash.
I believe that the version of libssh in multipass may not be the latest one (probably 0.90). Hence, please forgive the noise if this issue has already been cleared.
Otherwise, https://github.com/canonical/multipass/issues/1259 may constitute a pointer for a bug in libssh.