I recompiled without the policykit use flag.

Here goes :

error: You must be root to install this plugin.
sylvain@funtootux ~/hplip-3.12.4-plugin $ su -


funtootux hplip-3.12.4-plugin # ./hplip-plugin-install -i -l debug


Do you accept the license terms for the plug-in (y=yes*, n=no, q=quit) ? 
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_1000.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_1005_series.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_1018.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_1020.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_p1005.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_p1006.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_p1007.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_p1008.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_p1505.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_professional_p1102.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_professional_p1102w.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /lib/udev/rules.d/86-hpmud-hp_laserjet_professional_p1566.rules already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/scan/plugins/bb_marvell-x86_64.so already exists. Replacing.
hplip-plugin-install[26390]: debug: Symlink already exists. Replacing.
hplip-plugin-install[26390]: debug: Creating symlink /usr/share/hplip/scan/plugins/bb_marvell.so (link) to file /usr/share/hplip/scan/plugins/bb_marvell-x86_64.so (target)...
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/scan/plugins/bb_soap-x86_64.so already exists. Replacing.
hplip-plugin-install[26390]: debug: Symlink already exists. Replacing.
hplip-plugin-install[26390]: debug: Creating symlink /usr/share/hplip/scan/plugins/bb_soap.so (link) to file /usr/share/hplip/scan/plugins/bb_soap-x86_64.so (target)...
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/scan/plugins/bb_soapht-x86_64.so already exists. Replacing.
hplip-plugin-install[26390]: debug: Symlink already exists. Replacing.
hplip-plugin-install[26390]: debug: Creating symlink /usr/share/hplip/scan/plugins/bb_soapht.so (link) to file /usr/share/hplip/scan/plugins/bb_soapht-x86_64.so (target)...
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/fax/plugins/fax_marvell-x86_64.so already exists. Replacing.
hplip-plugin-install[26390]: debug: Symlink already exists. Replacing.
hplip-plugin-install[26390]: debug: Creating symlink /usr/share/hplip/fax/plugins/fax_marvell.so (link) to file /usr/share/hplip/fax/plugins/fax_marvell-x86_64.so (target)...
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_1000.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_1005_series.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_1018.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_1020.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1005.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1006.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1007.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1008.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1009.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_p1505.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102w.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/firmware/hp_laserjet_professional_p1566.fw.gz already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/data/plugins/license.txt already exists. Replacing.
hplip-plugin-install[26390]: debug: Target file /usr/share/hplip/prnt/plugins/lj-x86_64.so already exists. Replacing.
hplip-plugin-install[26390]: debug: Symlink already exists. Replacing.
hplip-plugin-install[26390]: debug: Creating symlink /usr/share/hplip/prnt/plugins/lj.so (link) to file /usr/share/hplip/prnt/plugins/lj-x86_64.so (target)...
hplip-plugin-install[26390]: debug: Updating hplip.conf - installed = 1
hplip-plugin-install[26390]: debug: Unable to open file /var/lib/hp/hplip.state for writing.
hplip-plugin-install[26390]: debug: Updating hplip.conf - eula = 1
hplip-plugin-install[26390]: debug: Unable to open file /var/lib/hp/hplip.state for writing.
hplip-plugin-install[26390]: debug: Unable to open file /var/lib/hp/hplip.state for writing.


I think that /var/lib/hp should exist before trying to write inside it.