I'm on a freshly installed Ubuntu 17.10, using Darcs 2.12.5 fron the
ubuntu packages, and I did a first clone of http:://darcs.net which went
as expected. Now the second clone (or the reviewed repo) is lasting much
more time at the patches copying step, which really makes the cache
system seem pointless.
Attached is the end of the output of strace.
Have you noticed all the unlink calls, e.g.
= -1 ENOENT (No such file or directory)
They are the vast majority of the file accesses and they all fail. I
would guess that this is what is slowing things down, but I have no idea
why darcs wants to delete these files.