[Dovecot] Permission denied after dist-upgrade

[Thomas Skowron]

> Another thing I thought of was chrooting, but I don't see any chrooting in your config.
> 
> Maybe you could find out something interesting by starting Dovecot with "strace -f -o log dovecot".

15311 setresgid(-1, 5000, -1)           = 0 
15311 setresuid(-1, 5000, -1)           = 0
15311 alarm(30)                         = 0
15311 chdir("/home/vmail/XXX/thomas") = -1 EACCES (Permission denied)
15311 alarm(0)                          = 30
15311 geteuid()                         = 5000
15311 geteuid()                         = 5000
15311 open("/etc/passwd", O_RDONLY|O_CLOEXEC) = -1 EACCES (Permission denied)
15311 getegid()                         = 5000
15311 getegid()                         = 5000
15311 open("/etc/group", O_RDONLY|O_CLOEXEC) = -1 EACCES (Permission denied)
15311 stat("/home/vmail/XXX/thomas", 0x7fffd3a4c4a0) = -1 EACCES (Permission denied)
15311 stat("/home/vmail/XXX", 0x7fffd3a4c4a0) = -1 EACCES (Permission denied)
15311 stat("/home/vmail", 0x7fffd3a4c4a0) = -1 EACCES (Permission denied)
15311 stat("/home", 0x7fffd3a4c4a0)     = -1 EACCES (Permission denied)
15311 stat("", 0x7fffd3a4c4a0)          = -1 ENOENT (No such file or directory)
15311 time(NULL)                        = 1297888629
15311 stat("/etc/localtime", 0x7fffd3a4c100) = -1 EACCES (Permission denied)
15311 open("/etc/localtime", O_RDONLY)  = -1 EACCES (Permission denied)


Is setresgid(-1,5000,-1) correct? I mean: -1!?