Refiz para mostrar o log:
julio@julio-S14BW01:~$ cd /tmp/
julio@julio-S14BW01:/tmp$ sudo apt-get install linux-headers-`uname -r`
[sudo] senha para julio:
Lendo listas de pacotes... Pronto
Construindo árvore de dependências
Lendo informação de estado... Pronto
linux-headers-4.15.0-43-generic is already the newest version (4.15.0-43.46).
0 pacotes atualizados, 0 pacotes novos instalados, 0 a serem removidos e 35 não atualizados.
julio@julio-S14BW01:/tmp$ bits=`getconf LONG_BIT`
julio@julio-S14BW01:/tmp$ wget https://www.dev47apps.com/files/600/droidcam-${bits}bit.tar.bz2
--2019-01-20 18:56:18-- https://www.dev47apps.com/files/600/droidcam-64bit.tar.bz2
Resolvendo www.dev47apps.com (www.dev47apps.com)... 198.252.107.38
Conectando-se a www.dev47apps.com (www.dev47apps.com)|198.252.107.38|:443... conectado.
A requisição HTTP foi enviada, aguardando resposta... 200 OK
Tamanho: 435822 (426K) [application/x-bzip]
Salvando em: “droidcam-64bit.tar.bz2”
droidcam-64bit.tar. 100%[===================>] 425,61K 200KB/s em 2,1s
2019-01-20 18:56:22 (200 KB/s) - “droidcam-64bit.tar.bz2” salvo [435822/435822]
julio@julio-S14BW01:/tmp$ [[ ${bits} -eq 32 ]] && checksum=20166fd23adfc826e26952d0837a2df1
julio@julio-S14BW01:/tmp$ [[ ${bits} -eq 64 ]] && checksum=525718dab42ad5868a67844736bd3c6c
julio@julio-S14BW01:/tmp$ echo "${checksum} droidcam-${bits}bit.tar.bz2" | md5sum -c --
droidcam-64bit.tar.bz2: SUCESSO
julio@julio-S14BW01:/tmp$ # OK?
julio@julio-S14BW01:/tmp$ tar xjf droidcam-${bits}bit.tar.bz2
julio@julio-S14BW01:/tmp$ cd droidcam-${bits}bit/
julio@julio-S14BW01:/tmp/droidcam-64bit$ sudo ./install
Webcam parameters: '640' and '480'
Building v4l2loopback-dc.ko
make: Entering directory '/tmp/droidcam-64bit/v4l2loopback'
make -C /lib/modules/`uname -r`/build M=`pwd`
make[1]: Entering directory '/usr/src/linux-headers-4.15.0-43-generic'
CC [M] /tmp/droidcam-64bit/v4l2loopback/v4l2loopback-dc.o
Building modules, stage 2.
MODPOST 1 modules
CC /tmp/droidcam-64bit/v4l2loopback/v4l2loopback-dc.mod.o
LD [M] /tmp/droidcam-64bit/v4l2loopback/v4l2loopback-dc.ko
make[1]: Leaving directory '/usr/src/linux-headers-4.15.0-43-generic'
make: Leaving directory '/tmp/droidcam-64bit/v4l2loopback'
Moving driver and executable to system folders
Registering webcam device
insmod: ERROR: could not insert module /lib/modules/4.15.0-43-generic/kernel/drivers/media/video/v4l2loopback-dc.ko: Required key not available
julio@julio-S14BW01:/tmp/droidcam-64bit$