Repo keeps a small number of settings that apply to the current user rather than to one checkout. They live in the per-user configuration file ~/.repoconfig/config, which is separate from both git's own ~/.gitconfig and the per-checkout settings stored in .repo/manifests.git/config (see internal-fs-layout.md for those).
The file is .repoconfig/config inside the user's home directory. The parent directory can be changed by setting the REPO_CONFIG_DIR environment variable, in which case repo reads $REPO_CONFIG_DIR/.repoconfig/config instead.
The file is created on demand; it's fine for it to be missing.
The file uses the git-config syntax. The easiest way to manage it is the repo config command:
# Set a value. repo config set sync.smartsync true # Read a value. repo config get sync.smartsync # Remove a value. repo config unset sync.smartsync # Show all settings. repo config list
Like other repo subcommands, repo config must be run from inside a repo checkout. The file can also be edited by hand:
[sync] smartsync = true
Boolean settings accept true/yes and false/no.
alias.<name> defines repo <name> as a shortcut for another subcommand, optionally with arguments, in the same way as git aliases:
[alias] ss = sync -s st = status -o
Aliases defined in a checkout's .repo/config take precedence over per-user ones. Existing subcommands cannot be overridden by an alias.
sync.smartsync is a boolean that lets a user decide once, for all their checkouts, whether repo sync should Smart Sync by default: true always Smart Syncs, as if -s/--smart-sync were passed; false never does by default, even if the manifest sets sync-smartsync="true"; unset follows the manifest.
The effective behavior is resolved in this order; the first match wins:
-s/--smart-sync, --no-smart-sync, or -t/--smart-tag.sync.smartsync in ~/.repoconfig/config.sync-smartsync="true" on the <default> element.So sync.smartsync=false turns off the manifest-driven default, but an explicit repo sync -s, repo sync -t TAG or repo smartsync still works. Likewise sync.smartsync=true is overridden by --no-smart-sync.
A Smart Sync enabled by sync.smartsync=true is treated as an explicit request: it is subject to the same restrictions as -s (it is skipped when -l/--local-only, -m/--manifest-name, -t/--smart-tag or --superproject-revision is used), and a failure to obtain a manifest from the server fails the sync instead of silently falling back to ToT.
sync.smartsync does not affect -l/--local-only: a local-only sync keeps whatever smart_sync_override.xml the previous network sync left behind. See smart-sync.md for details.