Header / Footer Options - pointer argument is not a valid pointer

[brownd7522]

Trying to set a footer / header margin causes the following error ":pointer argument is not a valid pointer".

Below is some of the inputs I have tried, I'm not sure if this is a bug or am I doing something wrong?

options = Libxlsxwriter::HeaderFooterOptions
worksheet.set_header_opt('&L&A&CPage &P of &N', options)
worksheet.set_footer_opt('&L&A&CPage` &P of &N', {margin: 0.2} )
worksheet.set_footer_opt('&L&A&CPage` &P of &N', {0.2} )
worksheet.set_footer_opt('&L&A&CPage` &P of &N', 0.2 )

Using set_header / set_footer works fine.