1. Summarise the issue (what were doing, what went wrong?)
Pushing alexdarcy/org-test leads to disproportionate RAM usage. It crashes my computer (16Gb RAM) and Simon had to kill it after 20Gb.
It can be reproduced by cloning and pushing it to hub.darcs.net.
 
This repo has been imported from git with git fast-export --all --progress 500 | darcs convert import.

Its size is 712M of which 649M is _darcs; it contains 1367 patches including many multi-megabyte patches.

2. What behaviour were you expecting instead?
Consume a reasonable RAM amount !

3. What darcs version are you using? (Try: darcs --exact-version)
2.18.3 (GHC 9.2.8)
Simon reproduces the issue with darcs 2.16 (ghc 8.10.7) and darcs 2.18.3 (ghc 9.8.2)

4. What operating system are you running?
 Gentoo

Some quick notes from investigating a little bit:

I tried it locally (push from this repo to an empty repo) and the
darcs process peaked at about 11G.

A workaround is to push in smaller chunks but obviously we should
be able to do better.

I guess that this has come up before but I haven't looked for tickets.