bundle2: introduce a specific function for bundling debug message
The bundling process is very verbose, we would like to be able to hide such
output behind a configuration flag and have it more explicitly referencing
bundle2. The first step is to gather all these messages in a dedicated
function.
The same gathering will be later do for debug message issue by unbundling.
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ ls
a
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
B should disappear
$ ls
a