PHP exec : dirvish default error (23) -- partial transfer - php

Question

I have web services that are used for backups, but since the move to PHP7 (?) The backup no longer works.
All web services links work.
I isolated the code that is a problem in PHP 7 but it can come from something else!
<?php
//$outputShell=shell_exec('sudo cat /etc/passwd');
exec('sudo /usr/sbin/dirvish --vault L106',$outputShell, $codeErreur);
//exec('sudo cat /etc/passwd',$outputShell, $codeErreur);
//
if ($codeErreur == 0){
var_dump ("ok",$outputShell,$codeErreur);
}
else{
var_dump ("nook",$outputShell,$codeErreur);
}
?>
When I execute this code directly via a browser I have this error:
dirvish error: branch /san/pcdsi/L106:default image 20190221154124
failed dirvish L106:default error (23) -- partial transfer expr:
syntax error expr: non-integer argument dirvish error: branch
/san/pcdsi/L106:default image 20190221154136 failed
and log dirvish
rsync_error: * Execution cycle 0 rsync: change_dir
"/mnt/pc-backup/L106/Users/" failed: No such file or directory (2)
rsync error: some files/attrs were not transferred (see previous
errors) (code 23) at main.c(1668) [Receiver=3.1.2] rsync: [Receiver]
write error: Broken pipe (32) Execution cycle 1 * rsync:
change_dir "/mnt/pc-backup/L106/Users/" failed: No such file or
directory (2) rsync error: some files/attrs were not transferred (see
previous errors) (code 23) at main.c(1668) [Receiver=3.1.2] rsync:
[Receiver] write error: Broken pipe (32)
If I run the / usr / sbin / dirvish --vault L106 command in root, the backup is done without any problem !!
In addition the part in a comment that I tested via cat / etc / passwd works!
Of course, I checked the rights sudo and the script being launched via a browser www-data is sudo without password ... no problem on this side there
On my old PHP 5 server, this PHP code works!
Do you have an idea? I hold?
- system problem?
- PHP problem?
- dirvish problem on PHP 7 platform?
In short, the exec command ('sudo / usr / sbin / dirvish --vault L106', $ outputShell, $ errorCode); works in PHP 5 and not in PHP 7!!