Comment 4 for bug 971476

Thanks for reporting this. I just had the same experience when following the instructions at http://www.4store.org/trac/wiki/CreateDatabase, and reading your posts saved me a good amount of work looking around for how it was supposed to work.

I was going to create the directory manually, but having this error message gave me the impression that the package was unmaintained or something.

However running the init script is not enough:
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20:58:18 rdf$ sudo /etc/init.d/4store start
[sudo] password for user:
 * Starting 4s-backend 4s-backend 4store[22419]: lock.c:38 failed to open metadata file /var/lib/4store/default/metadata.nt for locking: No such file or directory
4store[22419]: 1: /usr/bin/4s-backend() [0x411811]
4store[22419]: 2: /usr/bin/4s-backend() [0x403a0b]
4store[22419]: 3: /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7fbde7a9176d]
4store[22419]: 4: /usr/bin/4s-backend() [0x403a59]
21:06:19 rdf$
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The problem here is that, although /var/lib/4store is created, /var/lib/4store/default is not.
That directory would be created with the 4s-backend-setup command as explained 4store's wiki, but it can not succeed until /var/lib/4store exists.
The knowledge base name is defined in the start script as "default". It can be created in the normal way with:
sudo 4s-backend-setup default
After this, the init script runs fine.

Creating /var/lib/4store in the postinst script as you (Osma) proposed would make the whole thing straightforward.
Is there any reason not to do that, or was it a simple oversight?