module mapper: repository root

[Alexander Christensen]

Hi,

In the documentation for the C++module mapper at https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Module-Mapper.html, under the section 'file[?ident]' there is a mentioning of '$root' parameter inside a module mapping file, which is used to specify a repository root.

However, I don't understand what this means, and attempts to use it so far has failed for me.

Could anybody perhaps explain what is means, as well as provide an example syntax? That would be greatly appreciated.

Thanks in advance.

Best,
Alexander