[Haskell-cafe] Problem with stack

[Olaf Klinke]

On Thu, 2021-02-25 at 16:59 +0100, Sven Panne wrote:
> Am Do., 25. Feb. 2021 um 15:59 Uhr schrieb Olaf Klinke <
> olf at aatal-apotheke.de>:
> 
> > Speaking of which, is there a specification about what filesystem
> > features stack and its sub-tools expect? I can not build stack projects
> > on a remote cifs share, but on the local filesystem it works fine. The
> > error is
> > 
> > Encountered error while migrating Stack database:
> >     SQLite3 returned ErrorBusy while attempting to perform step:
> > database is locked
> > Please report this on https://github.com/commercialhaskell/stack/issues
> > [...]
> > 
> 
> In ancient times, locking over NFS didn't work, or at least not reliably.
> With NFS 4, locking was added to the protocol IIRC, but I have no clue how
> good it works, especially when you mix various platforms/implementations.
> What the current state with CIFS regarding locking is: I don't know, but in
> general I don't really trust remote file systems in this area. :-}

Thanks for the clue. 

So what exactly is "locking" on the file-system level, then? I searched
and found the term "oplocks" and that this is an option for cifs. Which
state does stack need? oplock=on or oplock=off? My SMB server currently
has oplock=on. Tried toggling it, still same SQLite3 locking error. 

And yes, I'd rather sooner than later switch over to NFS 4, but I have
to sort that out on my NAS. 

It's a pity, my approach was to have as much of my Haskell stuff on a
NAS as possible, so I wouldn't run into disk space issues. But this and
the fact that stack/ghc stubbornly insist on using local dirs like /tmp
make this hard. Has anynone else here successfully built a stack
project on a cifs share? 

Olaf

P.S.: Yes, I even re-mapped /tmp to another partition once to bootstrap
ghc because it would occupy my entire tmpfs. But it would be nice if
one could do without such tricks.