The following exception occurs when trying to render the thumbnail images for two macros:
```
[03-Jun-2014 23:01:17 UTC] [2014-06-04 09:01:17] EXCEPTION: (CommandException) Command failed with error #137!
COMMAND
convert '/tmp/8it37r5s2jok0kkg/11351-vbdrNb' -coalesce -resize '280'X'186.375''!' '/tmp/2855ast2qn28csoc/11351-GxEHPy'
STDOUT
(empty)
STDERR
(empty) at [/usr/src/libphutil/src/future/exec/ExecFuture.php:398]
[03-Jun-2014 23:01:17 UTC] #0 ExecFuture::resolvex() called at [/usr/src/phabricator/src/applications/files/PhabricatorImageTransformer.php:438]
[03-Jun-2014 23:01:17 UTC] #1 PhabricatorImageTransformer::applyScaleWithImagemagick(Object PhabricatorFile, 280, 210) called at [/usr/src/phabricator/src/applications/files/PhabricatorImageTransformer.php:140]
[03-Jun-2014 23:01:17 UTC] #2 PhabricatorImageTransformer::crudelyScaleTo(Object PhabricatorFile, 280, 210) called at [/usr/src/phabricator/src/applications/files/PhabricatorImageTransformer.php:27]
[03-Jun-2014 23:01:17 UTC] #3 PhabricatorImageTransformer::executeThumbTransform(Object PhabricatorFile, 280, 210) called at [/usr/src/phabricator/src/applications/files/controller/PhabricatorFileTransformController.php:156]
[03-Jun-2014 23:01:17 UTC] #4 PhabricatorFileTransformController::executeThumbTransform(Object PhabricatorFile, 280, 210) called at [/usr/src/phabricator/src/applications/files/controller/PhabricatorFileTransformController.php:63]
[03-Jun-2014 23:01:17 UTC] #5 PhabricatorFileTransformController::processRequest() called at [/usr/src/phabricator/webroot/index.php:95]
```