fails:Process.exec raises Errno::ENOENT for an empty string
fails:Process.exec raises Errno::ENOENT for a command which does not exist
fails:Process.exec raises an ArgumentError if the command includes a null byte
fails:Process.exec raises Errno::EACCES when the file does not have execute permissions
fails:Process.exec raises Errno::EACCES when passed a directory
fails:Process.exec runs the specified command, replacing current process
fails:Process.exec sets the current directory when given the :chdir option
fails:Process.exec flushes STDOUT upon exit when it's not set to sync
fails:Process.exec flushes STDERR upon exit when it's not set to sync
fails:Process.exec with a single argument subjects the specified command to shell expansion
fails:Process.exec with a single argument creates an argument array with shell parsing semantics for whitespace
fails:Process.exec with multiple arguments does not subject the arguments to shell expansion
fails:Process.exec (environment variables) sets environment variables in the child environment
fails:Process.exec (environment variables) unsets environment variables whose value is nil
fails:Process.exec (environment variables) coerces environment argument using to_hash
fails:Process.exec (environment variables) unsets other environment variables when given a true :unsetenv_others option
fails:Process.exec with a command array uses the first element as the command name and the second as the argv[0] value
fails:Process.exec with a command array coerces the argument using to_ary
fails:Process.exec with a command array raises an ArgumentError if the Array does not have exactly two elements
