Fix type error with null descriptions, fixes #10924

src/Composer/Command/ShowCommand.php

@@ -1070,7 +1070,12 @@ EOT
         foreach ($arrayTree as $package) {
             $io->write(sprintf('<info>%s</info>', $package['name']), false);
             $io->write(' ' . $package['version'], false);
+            if (isset($package['description'])) {
                 $io->write(' ' . strtok($package['description'], "\r\n"));
+            } else {
+                // output newline
+                $io->write('');
+            }
 
             if (isset($package['requires'])) {
                 $requires = $package['requires'];