diff --git a/readthedocs/builds/migrations/0007_make-build-command-result-attrs-nullable.py b/readthedocs/builds/migrations/0007_make-build-command-result-attrs-nullable.py
new file mode 100644
index 00000000000..564c742b31b
--- /dev/null
+++ b/readthedocs/builds/migrations/0007_make-build-command-result-attrs-nullable.py
@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.16 on 2018-12-19 21:49
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('builds', '0006_add_config_field'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='buildcommandresult',
+            name='end_time',
+            field=models.DateTimeField(blank=True, default=None, null=True, verbose_name='End time'),
+        ),
+        migrations.AlterField(
+            model_name='buildcommandresult',
+            name='exit_code',
+            field=models.IntegerField(blank=True, default=None, null=True, verbose_name='Command exit code'),
+        ),
+    ]
diff --git a/readthedocs/builds/models.py b/readthedocs/builds/models.py
index 93678975232..ccd84025564 100644
--- a/readthedocs/builds/models.py
+++ b/readthedocs/builds/models.py
@@ -606,10 +606,14 @@ class BuildCommandResult(BuildCommandResultMixin, models.Model):
     command = models.TextField(_('Command'))
     description = models.TextField(_('Description'), blank=True)
     output = models.TextField(_('Command output'), blank=True)
-    exit_code = models.IntegerField(_('Command exit code'))
+    exit_code = models.IntegerField(
+        _('Command exit code'), null=True, blank=True, default=None
+    )
 
     start_time = models.DateTimeField(_('Start time'))
-    end_time = models.DateTimeField(_('End time'))
+    end_time = models.DateTimeField(
+        _('End time'), null=True, blank=True, default=None
+    )
 
     class Meta(object):
         ordering = ['start_time']
@@ -628,3 +632,4 @@ def run_time(self):
         if self.start_time is not None and self.end_time is not None:
             diff = self.end_time - self.start_time
             return diff.seconds
+        return None
diff --git a/readthedocs/builds/static-src/builds/js/detail.js b/readthedocs/builds/static-src/builds/js/detail.js
index 58637d6b1ee..2df3e206399 100644
--- a/readthedocs/builds/static-src/builds/js/detail.js
+++ b/readthedocs/builds/static-src/builds/js/detail.js
@@ -9,8 +9,8 @@ function BuildCommand(data) {
     self.id = ko.observable(data.id);
     self.command = ko.observable(data.command);
     self.output = ko.observable(data.output);
-    self.exit_code = ko.observable(data.exit_code || 0);
-    self.successful = ko.observable(self.exit_code() === 0);
+    self.exit_code = ko.observable(data.exit_code);
+    self.successful = ko.observable(self.exit_code() === null || self.exit_code() === 0);
     self.run_time = ko.observable(data.run_time);
     self.is_showing = ko.observable(!self.successful());
 
@@ -23,6 +23,10 @@ function BuildCommand(data) {
             'build-command-successful' :
             'build-command-failed';
     });
+
+    self.is_running = ko.computed(function () {
+        return self.exit_code() !== null && self.run_time() != null;
+    });
 }
 
 function BuildDetailView(instance) {
@@ -83,6 +87,10 @@ function BuildDetailView(instance) {
                 );
                 if (!match) {
                     self.commands.push(command);
+                } else {
+                    match.output = command.output;
+                    match.exit_code = command.exit_code;
+                    match.run_time = command.run_time;
                 }
             }
         });
diff --git a/readthedocs/doc_builder/environments.py b/readthedocs/doc_builder/environments.py
index d48fc73641f..f1b31bda44c 100644
--- a/readthedocs/doc_builder/environments.py
+++ b/readthedocs/doc_builder/environments.py
@@ -97,6 +97,7 @@ class BuildCommand(BuildCommandResultMixin):
     def __init__(self, command, cwd=None, shell=False, environment=None,
                  combine_output=True, input_data=None, build_env=None,
                  bin_path=None, description=None, record_as_success=False):
+        self.command_id = None
         self.command = command
         self.shell = shell
         if cwd is None:
@@ -249,6 +250,18 @@ def get_command(self):
 
     def save(self):
         """Save this command and result via the API."""
+        self.start_time = self.start_time or datetime.utcnow()
+        data = {
+            'build': self.build_env.build.get('id'),
+            'command': self.get_command(),
+            'description': self.description,
+            'start_time': self.start_time,
+        }
+        resp = api_v2.command.post(data)
+        self.command_id = resp['id']
+
+    def update(self):
+        """Update this command and result via the API."""
         # Force record this command as success to avoid Build reporting errors
         # on commands that are just for checking purposes and do not interferes
         # in the Build
@@ -257,15 +270,11 @@ def save(self):
             self.exit_code = 0
 
         data = {
-            'build': self.build_env.build.get('id'),
-            'command': self.get_command(),
-            'description': self.description,
             'output': self.output,
             'exit_code': self.exit_code,
-            'start_time': self.start_time,
             'end_time': self.end_time,
         }
-        api_v2.command.post(data)
+        api_v2.command(self.command_id).patch(data)
 
 
 class DockerBuildCommand(BuildCommand):
@@ -363,6 +372,9 @@ def __init__(self, project, environment=None):
     def record_command(self, command):
         pass
 
+    def update_command(self, command):
+        pass
+
     def run(self, *cmd, **kwargs):
         """Shortcut to run command from environment."""
         return self.run_command_class(cls=self.command_class, cmd=cmd, **kwargs)
@@ -404,13 +416,15 @@ def run_command_class(
         # ``build_env`` is passed as ``kwargs`` when it's called from a
         # ``*BuildEnvironment``
         build_cmd = cls(cmd, **kwargs)
+        if record:
+            self.record_command(build_cmd)
         build_cmd.run()
 
         if record:
             # TODO: I don't like how it's handled this entry point here since
             # this class should know nothing about a BuildCommand (which are the
             # only ones that can be saved/recorded)
-            self.record_command(build_cmd)
+            self.update_command(build_cmd)
 
             # We want append this command to the list of commands only if it has
             # to be recorded in the database (to keep consistency) and also, it
@@ -559,6 +573,9 @@ def handle_exception(self, exc_type, exc_value, _):
     def record_command(self, command):
         command.save()
 
+    def update_command(self, command):
+        command.update()
+
     def run(self, *cmd, **kwargs):
         kwargs.update({
             'build_env': self,
diff --git a/readthedocs/rtd_tests/tests/test_builds.py b/readthedocs/rtd_tests/tests/test_builds.py
index 53e222203fe..e4c1eaf0bdf 100644
--- a/readthedocs/rtd_tests/tests/test_builds.py
+++ b/readthedocs/rtd_tests/tests/test_builds.py
@@ -44,6 +44,10 @@ def test_build(self, load_config):
         self.mocks.configure_mock('api', {
             'get.return_value': {'downloads': "no_url_here"}
         })
+        self.mocks.configure_mock('api_versions', {'return_value': [version]})
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
         self.mocks.patches['html_build'].stop()
 
         build_env = LocalBuildEnvironment(project=project, version=version, build={})
@@ -188,6 +192,9 @@ def test_build_pdf_latex_failures(self, load_config):
         load_config.side_effect = create_load()
         self.mocks.patches['html_build'].stop()
         self.mocks.patches['pdf_build'].stop()
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         project = get(Project,
                       slug='project-1',
@@ -234,6 +241,9 @@ def test_build_pdf_latex_not_failure(self, load_config):
         load_config.side_effect = create_load()
         self.mocks.patches['html_build'].stop()
         self.mocks.patches['pdf_build'].stop()
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         project = get(Project,
                       slug='project-2',
diff --git a/readthedocs/rtd_tests/tests/test_doc_building.py b/readthedocs/rtd_tests/tests/test_doc_building.py
index 6a954de74d6..46a4d30d6d4 100644
--- a/readthedocs/rtd_tests/tests/test_doc_building.py
+++ b/readthedocs/rtd_tests/tests/test_doc_building.py
@@ -69,6 +69,9 @@ def test_normal_execution(self):
         self.mocks.configure_mock('process', {
             'communicate.return_value': (b'This is okay', '')
         })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
         type(self.mocks.process).returncode = PropertyMock(return_value=0)
 
         build_env = LocalBuildEnvironment(
@@ -87,15 +90,17 @@ def test_normal_execution(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 0,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -155,6 +160,9 @@ def test_record_command_as_success(self):
         self.mocks.configure_mock('process', {
             'communicate.return_value': (b'This is okay', '')
         })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
         type(self.mocks.process).returncode = PropertyMock(return_value=1)
 
         build_env = LocalBuildEnvironment(
@@ -173,15 +181,17 @@ def test_record_command_as_success(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 0,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -239,6 +249,9 @@ def test_failing_execution(self):
         self.mocks.configure_mock('process', {
             'communicate.return_value': (b'This is not okay', '')
         })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
         type(self.mocks.process).returncode = PropertyMock(return_value=1)
 
         build_env = LocalBuildEnvironment(
@@ -258,15 +271,17 @@ def test_failing_execution(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 1,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -556,6 +571,9 @@ def test_api_failure_on_docker_memory_limit(self):
                     'Failure creating container', response,
                     'Failure creating container'),
             })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         build_env = DockerBuildEnvironment(
             version=self.version,
@@ -572,15 +590,17 @@ def test_api_failure_on_docker_memory_limit(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': -1,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -680,6 +700,9 @@ def test_command_execution(self):
                 'exec_start.return_value': b'This is the return',
                 'exec_inspect.return_value': {'ExitCode': 1},
             })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         build_env = DockerBuildEnvironment(
             version=self.version,
@@ -700,15 +723,17 @@ def test_command_execution(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 1,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -775,6 +800,9 @@ def test_record_command_as_success(self):
                 'exec_start.return_value': b'This is the return',
                 'exec_inspect.return_value': {'ExitCode': 1},
             })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         build_env = DockerBuildEnvironment(
             version=self.version,
@@ -795,15 +823,17 @@ def test_record_command_as_success(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 0,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -835,6 +865,9 @@ def test_command_execution_cleanup_exception(self):
                     'Failure killing container',
                 )
             })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         build_env = DockerBuildEnvironment(
             version=self.version,
@@ -850,15 +883,17 @@ def test_command_execution_cleanup_exception(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 0,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
@@ -939,6 +974,9 @@ def test_container_timeout(self):
                 'exec_start.return_value': b'This is the return',
                 'exec_inspect.return_value': {'ExitCode': 0},
             })
+        self.mocks.configure_mock(
+            'api_v2.command', {'post.return_value': {'id': 1}}
+        )
 
         build_env = DockerBuildEnvironment(
             version=self.version,
@@ -954,15 +992,17 @@ def test_container_timeout(self):
 
         # api() is not called anymore, we use api_v2 instead
         self.assertFalse(self.mocks.api()(DUMMY_BUILD_ID).put.called)
-        # The command was saved
+        # The command was saved and updated
         command = build_env.commands[0]
         self.mocks.mocks['api_v2.command'].post.assert_called_once_with({
             'build': DUMMY_BUILD_ID,
             'command': command.get_command(),
             'description': command.description,
+            'start_time': mock.ANY,
+        })
+        self.mocks.mocks['api_v2.command']().patch.assert_called_once_with({
             'output': command.output,
             'exit_code': 0,
-            'start_time': command.start_time,
             'end_time': command.end_time,
         })
         self.mocks.mocks['api_v2.build']().put.assert_called_with({
diff --git a/readthedocs/templates/builds/build_detail.html b/readthedocs/templates/builds/build_detail.html
index 4aa528eaba0..d94b92171a2 100644
--- a/readthedocs/templates/builds/build_detail.html
+++ b/readthedocs/templates/builds/build_detail.html
@@ -190,11 +190,13 @@ <h3>{% trans "Error" %}</h3>
           </div>
           <div class="build-command-return"
                data-bind="visible: is_showing">
-            <div class="build-command-output">
+            <div class="build-command-output"
+                 data-bind="visible: is_running">
               <span data-bind="text: output"></span>
             </div>
 
-            <div class="build-command-meta">
+            <div class="build-command-meta"
+                 data-bind="visible: is_running">
               <span class="build-command-time">
                 {% trans "Command time:" %}
                 <span data-bind="text: run_time">0</span>s