Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets
`foo.bar` to the boolean true value (just like `[foo]bar` would in a
config file). Including the equals but with an empty value (like `git -c
-foo.bar= ...`) sets `foo.bar` to the empty string which ` git config
+foo.bar= ...`) sets `foo.bar` to the empty string which `git config
--bool` will convert to `false`.
--exec-path[=<path>]::