install: 'umount-cow-store' retries upon EBUSY....Possibly fixes <https://issues.guix.gnu.org/59884>.
* gnu/build/install.scm (umount*): New procedure.
(unmount-cow-store): Use it instead of 'umount'.
Ludovic Courtès
2022-11-15
install: Validate symlink target in evaluate-populate-directive....* gnu/build/install.scm (evaluate-populate-directive): By default, error when
the target of a symlink doesn't exist. Always ensure TARGET ends with "/".
(populate-root-file-system): Call evaluate-populate-directive with
#:error-on-dangling-symlink #t and add comment.