hackage-security cannot gracefully handle absence of package cache directory for file-based remote repositories

[ezyang]

Steps to reproduce:

1. In a directory, create .cabal/config file with the following contents:

repository foo-bar
    url: file:/home/ezyang/Dev/labs/localrepo/repo/
    secure: True
    root-keys:
    key-threshold: 0

remote-repo-cache: /home/ezyang/Dev/labs/raclette/.cabal/packages

But you'll need to adjust the two absolute paths to point to a local repository initialized using hackage-repo-tool and the .cabal/packages directory from your current working directory.

Then run HOME=$PWD cabal update and it will fail with:

cabal:
/home/ezyang/Dev/labs/raclette/.cabal/packages/foo-bar/hackage-security-lock:
does not exist

[23Skidoo]

/cc @edsko

[nomeata]

I just hit this in my experiment “can I make cabal use an additional, local repository”.

[nomeata]

BTW, it only happens with local repositories. If I run sws or some webserver in that directory, things work nicely.