Let background commands actually run in the background

app/code/Magento/Bundle/Test/Mftf/Test/AdminBundleDynamicAttributesAfterMassUpdateTest.xml

@@ -47,7 +47,7 @@
             <argument name="consumerName" value="{{AdminProductAttributeUpdateConsumerData.consumerName}}"/>
             <argument name="maxMessages" value="{{AdminProductAttributeUpdateConsumerData.messageLimit}}"/>
         </actionGroup>
-        <magentoCron stepKey="runCron"/>
+        <magentoCron groups="default" stepKey="runCron"/>
 
         <actionGroup ref="OpenProductForEditByClickingRowXColumnYInProductGridActionGroup" stepKey="openProductForEdit"/>
 

app/code/Magento/Catalog/Test/Mftf/Test/StorefrontVerifyProductAfterPartialReindexOnSeveralWebsitesTest.xml

@@ -87,9 +87,11 @@
             <argument name="productName" value="{{_defaultProduct.name}}"/>
         </actionGroup>
 
-        <!-- Run cron -->
-        <magentoCron stepKey="runCron" />
-        <magentoCron stepKey="runCronTwice" />
+        <!-- We need the 'indexer_update_all_views' job to run. This is the best
+            way we can make that happen, but there is no guarantee that there is
+            such a job already scheduled in the queue. -->
+        <magentoCron groups="index" stepKey="runCron" />
+        <comment userInput="We need the indexer_update_all_views job to run" stepKey="runCronTwice"/>
 
         <!-- Check product is present in category after cron run -->
         <actionGroup ref="AssertProductInStorefrontCategoryPage" stepKey="assertProductInStorefront1">

app/code/Magento/SalesRule/Test/Mftf/Test/StorefrontReuseCouponCodeAfterOrderCanceledTest.xml

@@ -94,7 +94,7 @@
             <argument name="orderNumberMessage" value="CONST.successCheckoutOrderNumberMessage"/>
             <argument name="emailYouMessage" value="CONST.successCheckoutEmailYouMessage"/>
         </actionGroup>
-        <magentoCron stepKey="runCronAfterPlacingOrder"/>
+        <magentoCron groups="default" stepKey="runCronAfterPlacingOrder"/>
 
         <!-- Get Order id -->
         <grabTextFrom selector="{{CheckoutSuccessMainSection.orderNumber22}}" stepKey="grabOrderNumber"/>
@@ -114,7 +114,7 @@
         <!-- Cancel order -->
         <actionGroup ref="CancelPendingOrderActionGroup" stepKey="cancelOrder"/>
         <waitForPageLoad stepKey="waitForOrderDetailsToLoad"/>
-        <magentoCron stepKey="runCronAfterCancelingOrder"/>
+        <magentoCron groups="default" stepKey="runCronAfterCancelingOrder"/>
 
         <!-- Open My Account Page from Customer dropdown -->
         <actionGroup ref="StorefrontOpenMyAccountPageActionGroup" stepKey="goToMyAccountPage"/>

lib/internal/Magento/Framework/Shell/CommandRendererBackground.php

@@ -35,6 +35,6 @@ public function render($command, array $arguments = [])
 
         return $this->osInfo->isWindows() ?
             'start /B "magento background task" ' . $command
-            : str_replace('2>&1', '> /dev/null &', $command);
+            : str_replace('2>&1', '2>/dev/null >/dev/null &', $command);
     }
 }

lib/internal/Magento/Framework/Shell/Test/Unit/CommandRendererBackgroundTest.php

@@ -59,7 +59,7 @@ public function commandPerOsTypeDataProvider()
     {
         return [
             'windows' => [true, 'start /B "magento background task" ' . $this->testCommand . ' 2>&1'],
-            'unix'    => [false, $this->testCommand . ' > /dev/null &'],
+            'unix'    => [false, $this->testCommand . ' 2>/dev/null >/dev/null &'],
         ];
     }
 }