A root is defined as a directory that contains a regular file
whose name matches a given pattern and which optionally contains a given text.
The search for a root starts at a given directory (the working directory
by default), and proceeds up the directory hierarchy.
get_root_desc() returns the description of the criterion
for a root path. This is especially useful for composite root criteria
created with |.root_criterion().
The normalized path of the root as specified by the search criterion.
Throws an error if no root is found
Details
Starting from the working directory, the find_root() function searches
for the root.
If a root is found, the ... arguments are used to construct a path;
thus, if no extra arguments are given, the root is returned.
If no root is found, an error is thrown.