Added support for legacy SCP protocol.

tbot/machine/connector/ssh.py

@@ -65,6 +65,16 @@ def ignore_hostkey(self) -> bool:
         """
         return False
 
+    @property
+    def requires_legacy_scp(self) -> bool:
+        """
+        Use the legacy SCP protocol for file transfers instead of the SFTP protocol.
+
+        Forcing the use of the SCP protocol may be necessary for servers that do not
+        implement SFTP, for backwards compatibility.
+        """
+        return False
+
     @property
     def use_multiplexing(self) -> bool:
         """

tbot/machine/linux/copy.py

@@ -31,6 +31,10 @@ def _scp_copy(
         *[arg for opt in ssh_config for arg in ["-o", opt]],
     ]
 
+    use_legacy_protocol = getattr(remote_path.host, "requires_legacy_scp", False)
+    if use_legacy_protocol:
+        scp_command += ["-O"]
+
     if use_multiplexing:
         multiplexing_dir = local_host.workdir / ".ssh-multi"
         scp_command += ["-o", "ControlMaster=auto"]