PHP Bad File Descriptor Error

Question

We've recently upgraded our servers from PHP 5.4.15 to 5.5.1 and have started getting this error in the logs

Fatal Error Unable to create lock file: Bad file descriptor

I've tracked it down to this bit a code that opens another small PHP script which uploads a file to S3 in the background.

// Grab uploaded file and assign a working name
$fileTemp = $_FILES['file']['tmp_name'];
$pathToWorkingFile = tempnam($g_TmpDirectory, "TR-");

// Move the file to our working area        
if (move_uploaded_file($fileTemp, $pathToWorkingFile) === false)
    throw new Exception("Cannot move file to staging area.", 1011);

// Where the file will end up on S3
$s3Bucket = "test.bucket.com";
$uploadDest = "/uploads/image123.jpg";

// Create process to upload file in background
popen("/usr/local/bin/php /path/to/uploadScript.php $pathToWorkingFile $s3Bucket $uploadDest &", 'r');

Answer 1

It turns out that this error was caused by our configuration of OPcache which was enabled during the PHP upgrade process. When I disable it for command line operations by removing this setting from php.ini everything works fine.

opcache.enable_cli=1

Answer 2

I was able to resolve with opcache.enable_cli=1, but for me the underlying problem was wrong permissions on the /tmp directory in MacOS.

This is what I did to fix this:

sudo rm -Rf /tmp
sudo rm -Rf /private/tmp
sudo mkdir /private/tmp
sudo chown root:wheel /private/tmp
sudo chmod 1777 /private/tmp
sudo ln -s /private/tmp /tmp