can't use from udev script

[dannybackx]

I'm trying to use jmtpfs from a udev script.

The command I'm running is
jmtpfs -o allow_other /media/danny/XT1068
and it produces this output :
Unable to open ~/.mtpz-data for reading, MTPZ disabled.
No mtp devices found.
The second line is on stderr.

This is not happening when I run the script from the command line. Any pointers ?

FYI the XT1068 is my new Moto G 2014, of which libmtp complains (see below) but I think this does no harm :
acer: {167} jmtpfs -l
Device 0 (VID=22b8 and PID=2e76) is UNKNOWN.
Please report this VID/PID and the device model to the libmtp development team
Unable to open ~/.mtpz-data for reading, MTPZ disabled.Available devices (busLocation, devNum, productId, vendorId, product, vendor):
3, 55, 0x2e76, 0x22b8, UNKNOWN, UNKNOWN