Over the years, there has unfortunately been some slowdown when using the repo reference command. We reported this issue [1] and for some time we temporarily checked out an earlier commit as a workaround. However, Google seemed to improved it again in later versions and although slower, it was acceptable.
However, we've noticed that things are running slower yet again. After some trail and error, we've concluded that adding the "--partial-clone" when running the "repo init" command together with "--reference" brings down the sync time to less than a minute again. Therefore from now on we recommend using that when using reference mirrors.
Over the years, there has unfortunately been some slowdown when using the repo reference command. We reported this issue [1] and for some time we temporarily checked out an earlier commit as a workaround. However, Google seemed to improved it again in later versions and although slower, it was acceptable.
However, we've noticed that things are running slower yet again. After some trail and error, we've concluded that adding the "--partial-clone" when running the "repo init" command together with "--reference" brings down the sync time to less than a minute again. Therefore from now on we recommend using that when using reference mirrors.
Link: https://issues.gerritcodereview.com/issues/40014651?pli=1 [1]