rrdtool fetch issue with rrdcached and unix socket

[earendilfr]

Describe the bug
I have a a strange issue with rrdtool and rrdcached.
I try to fetch data:

when I try to retrieve it through the TCP socket,it's working fine:

$ rrdtool fetch <device>/port-id4452.rrd AVERAGE --start now-800 --end now --daemon localhost:42217
                       INOCTETS           OUTOCTETS            INERRORS           OUTERRORS         INUCASTPKTS        OUTUCASTPKTS        INNUCASTPKTS       OUTNUCASTPKTS          INDISCARDS         OUTDISCARDS     INUNKNOWNPROTOS     INBROADCASTPKTS    OUTBROADCASTPKTS     INMULTICASTPKTS    OUTMULTICASTPKTS

1659724500: 2.6440111531e+04 3.0643290155e+04 0.0000000000e+00 0.0000000000e+00 9.0721785798e+01 9.3000295559e+01 -nan -nan 0.0000000000e+00 0.0000000000e+00 -nan 7.5942754919e-01 1.2849809131e+02 2.2139606440e+01 2.1586345182e+01
1659724800: 2.3870372267e+04 3.0900674729e+04 0.0000000000e+00 0.0000000000e+00 8.7565268466e+01 9.1373657930e+01 -nan -nan 0.0000000000e+00 0.0000000000e+00 -nan 7.7754919499e-01 1.2859880791e+02 2.2167525343e+01 2.1557375749e+01
1659725100: 2.2333918381e+04 3.0861986977e+04 0.0000000000e+00 0.0000000000e+00 8.6070902326e+01 9.0101060465e+01 -nan -nan 0.0000000000e+00 0.0000000000e+00 -nan 8.1860465116e-01 1.2887231628e+02 2.2211572093e+01 2.1502474419e+01
1659725400: -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan

But when I try with the unix socket, I receive a message that indicate that the file doesn't exist:

$ rrdtool fetch <device>/port-id4452.rrd AVERAGE --start now-800 --end now --daemon unix:/run/rrdcached.sock
ERROR: realpath(<device>/port-id4452.rrd): Aucun fichier ou dossier de ce type

And if I indicate the full path it's working fine:

$ rrdtool fetch /opt/librenms/rrd/<device>/port-id4452.rrd AVERAGE --start now-800 --end now --daemon unix:/run/rrdcached.sock
                       INOCTETS           OUTOCTETS            INERRORS           OUTERRORS         INUCASTPKTS        OUTUCASTPKTS        INNUCASTPKTS       OUTNUCASTPKTS          INDISCARDS         OUTDISCARDS     INUNKNOWNPROTOS     INBROADCASTPKTS    OUTBROADCASTPKTS     INMULTICASTPKTS    OUTMULTICASTPKTS

1659725400: 2.2009036977e+04 3.0347161739e+04 0.0000000000e+00 0.0000000000e+00 8.4773996433e+01 8.9116496767e+01 -nan -nan 0.0000000000e+00 0.0000000000e+00 -nan 8.4015607581e-01 1.2821055920e+02 2.2154971683e+01 2.0771030546e+01
1659725700: 2.2475673401e+04 2.9771365780e+04 0.0000000000e+00 0.0000000000e+00 8.5310682637e+01 8.9167404008e+01 -nan -nan 0.0000000000e+00 0.0000000000e+00 -nan 8.2434004822e-01 1.2650634933e+02 2.2121673278e+01 2.0331223717e+01
1659726000: -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan -nan

Did it's normal ?

Desktop (please complete the following information):

• OS: Debian 11
• rrdtool version: 1.7.2
• rrdcached version: 1.7.2

Configuration of rrdcached

# /etc/default file for RRD cache daemon

# Full path to daemon
DAEMON=/usr/bin/rrdcached

# Optional override flush interval, in seconds.
WRITE_TIMEOUT=1800

# Optional override maximum write delay, in seconds.
WRITE_JITTER=1800

# Optional override number of write_threads
WRITE_THREADS=4

# Where database files are placed.  If left unset, the default /tmp will
# be used.  NB: The daemon will reject a directory that has symlinks as
# components.  NB: You may want to have -B in BASE_OPTS.
BASE_PATH=/opt/librenms/rrd/

# Where journal files are placed.  If left unset, journaling will
# be disabled.
JOURNAL_PATH=/var/lib/rrdcached/journal/

# FHS standard placement for process ID file.
PIDFILE=/var/run/rrdcached.pid

# FHS standard placement for local control socket.
SOCKFILE=/run/rrdcached.sock

# Optional override group that should own/access the local control
# socket
SOCKGROUP=librenms

# Optional override access mode of local control socket.
#SOCKMODE=0660

# Optional unprivileged group to run under when daemon.  If unset
# retains invocation group privileges.
DAEMON_GROUP=librenms

# Optional unprivileged user to run under when daemon.  If unset
# retains invocation user privileges.
DAEMON_USER=librenms

# Network socket address requests.  Use in conjunction with SOCKFILE to
# also listen on INET domain sockets.  The option is a lower-case ell
# ASCII 108 = 0x6c, and should be repeated for each address.  The
# parameter is an optional IP address, followed by an optional port with
# a colon separating it from the address.  The empty string is
# interpreted as "open sockets on the default port on all available
# interfaces", but generally does not pass through init script functions
# so use -L with no parameters for that configuration.
#NETWORK_OPTIONS="-L"

# Any other options not specifically supported by the script (-P, -f,
# -F, -B).
BASE_OPTIONS="-B -F -R -L ''"