Git Hooks requires access to external commands
Git Cola is a Git frontend, one of the Git’s feature is that one can install executable hooks that are triggered in several conditions (like committing a new revision, push changes to a remote server, and preparing the commit message), these hooks can include/be any commands that simply can’t pack them all into a snap.
Git Attributes requires access to external commands
Git attributes are settings that can be specified for a certain path pattern under the repository, one of its usage is to set-up clean/smudge filter programs to clean-up/pre-process checked-in/out code, these filter programs can call any random commands that simply can’t pack them all into the snap.
These usages make Git frontend snaps not possible to be strictly confined without limiting its functionality. Thanks in advance!