This is my fbtrace.conf :

<database /var/databases/mlv2_ps4t.fdb>
enabled true
log_connections true
log_transactions true
log_statement_start true
</database>

used with the command :
fbtracemgr -se localhost/3050:service_mgr -user XXX -password xxx -start -name "marianne" -config fbtrace.conf

Wich result at screen with : Trace session ID 1 started

Then I connect with ibexpert to the database.
A that moment I see in the firebird log file :
Trace plugin libfbtrace.so returned error on call trace_create.
Error details: line 1: error while compiling regular expression "/var/databases/mlv2_ps4t.fdb"
Followed by ... :
Trace plugin libfbtrace.so returned error on call trace_create.
Error details: cannot initialize UNICODE collation to use in trace plugin

And when I ended the fbtracemgr , I can see in the firebird log file :
Trace plugin libfbtrace.so returned error on call trace_create.
Error details: line 1: error while compiling regular expression "/var/databases/mlv2_ps4t.fdb"

Shutting down the server with 0 active connection(s) to 0 database(s), 1 active service(s)



Marianne Castel

-----Message d'origine-----
De : Konstantin Khomoutov [mailto:flatworm@...]
Envoyé : mercredi 13 mars 2013 12:16
À : firebird-support@yahoogroups.com
Cc : Marianne
Objet : Re: [firebird-support] fbtrace - linux server

On Wed, 13 Mar 2013 11:28:26 +0100
<castel.m@...> wrote:

> Thanks Konstantin,
> Sorry for the darkness ... :-)
> Yes The server is a debian, just checked the version : 6.0.7 , that's
> a Squeeze and the firebird package was installed from the debian
> depot. Just checked firebird log file, and found this message : (not
> exactly the same as the one you gave in the debian bug report)
>
> "Trace plugin libfbtrace.so returned error on call trace_create.
> Error details: line 1: error while compiling regular
> expression "/var/databases/mlv2_ps4t.fdb""
>
> I'm now reading the bugreport/tracker posts.

No, this message usually results from invalid specification of the database in the trace configuration file.
Could you please post the exact contents of the file you're using (passwords and things like this culled, of course)?