The "open" command:
Usage: fossil open FILENAME ?VERSION? ?OPTIONS?
Open a connection to the local repository in FILENAME. A checkout
for the repository is created with its root at the working directory.
If VERSION is specified then that version is checked out. Otherwise
the latest version is checked out. No files other than "manifest"
and "manifest.uuid" are modified if the --keep option is present.
--keep Only modify the manifest and manifest.uuid files
--nested Allow opening a repository inside an opened checkout
See also: close