Capture the command's standard output stream to a file written to
the designated output directory.
If stdout is a string, it specifies the file name to use.
If stdout is an expression, the expression is evaluated and must
return a string with the file name to use to capture stdout. If the
return value is not a string, or the resulting path contains illegal
characters (such as the path separator /) it is an error.
Capture the command's standard output stream to a file written to the designated output directory. If stdout is a string, it specifies the file name to use. If stdout is an expression, the expression is evaluated and must return a string with the file name to use to capture stdout. If the return value is not a string, or the resulting path contains illegal characters (such as the path separator /) it is an error.