Merge pull request #11721 from jbonhag/f/ssh-nil-exit-status

Raise an error on nil exit status

lib/vagrant/errors.rb

@@ -812,6 +812,10 @@ module Vagrant
       error_key(:ssh_key_type_not_supported)
     end
 
+    class SSHNoExitStatus < VagrantError
+      error_key(:ssh_no_exit_status)
+    end
+
     class SSHNoRoute < VagrantError
       error_key(:ssh_no_route)
     end

plugins/communicators/ssh/communicator.rb

@@ -730,6 +730,11 @@ module VagrantPlugins
           yield :stdout, data if block_given?
         end
 
+        if !exit_status
+          @logger.debug("Exit status: #{exit_status.inspect}")
+          raise Vagrant::Errors::SSHNoExitStatus
+        end
+
         # Return the final exit status
         return exit_status
       end

templates/locales/en.yml

@@ -1460,6 +1460,11 @@ en:
         usually indicates that SSH within the guest machine was unable to
         properly start up. Please boot the VM in GUI mode to check whether
         it is booting properly.
+      ssh_no_exit_status: |-
+        The SSH command completed, but Vagrant did not receive an exit status.
+        This indicates that the command was terminated unexpectedly. Please
+        check that the VM has sufficient memory to run the command and that no
+        processes were killed by the guest operating system.
       ssh_no_route: |-
         While attempting to connect with SSH, a "no route to host" (EHOSTUNREACH)
         error was received. Please verify your network settings are correct

test/unit/plugins/communicators/ssh/communicator_test.rb

@@ -317,6 +317,15 @@ describe VagrantPlugins::CommunicatorSSH::Communicator do
       end
     end
 
+    context "with no exit code received" do
+      let(:exit_data) { double("exit_data", read_long: nil) }
+
+      it "raises error when exit code is nil" do
+        expect(command_channel).to receive(:send_data).with(/make\n/)
+        expect{ communicator.execute("make") }.to raise_error(Vagrant::Errors::SSHNoExitStatus)
+      end
+    end
+
     context "with garbage content prepended to command output" do
       let(:command_stdout_data) do
         "Line of garbage\nMore garbage\n#{command_garbage_marker}bin\ntmp\n"