Calamares fails in UEFI mode after external command in Lubuntu Cosmic - another computer

[sudodus]

This is tested in an Intel NUC6i3SYH. There is no optical drive (DVD) in the NUC, which is different from the Toshiba, that is tested in the related bug report,

https://bugs.launchpad.net/ubuntu/+source/calamares-settings-ubuntu/+bug/1781015

Calamares reached 78%, where is got stuck and timed out with the following error message:

---
Error

Installation failed

Command [ -d /sys/firmware/efi ] && chroot /tmp/calamares-root-jjkzku_z apt-cdrom add && chroot /tmp/calamares-root-jjkzku_z sed -e '/deb http/ s/^#*/#/' -i /etc/apt/sources.list && chroot /tmp/calamares-root-jjkzku_z apt update && chroot /tmp/calamares-root-jjkzku_z apt -y install grub-efi-amd64-bin && chroot /tmp/calamares-root-jjkzku_z sed -i 's/#deb/deb/' /etc/apt/sources.list || exit 0 failed to finish in 300 seconds. There was no output from the command.
---

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: calamares 3.2.1-1
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Uname: Linux 4.15.0-23-generic x86_64
ApportVersion: 2.20.10-0ubuntu5
Architecture: amd64
CasperVersion: 1.394
CurrentDesktop: LXQt
Date: Fri Jul 13 09:07:30 2018
LiveMediaBuild: Lubuntu 18.10 "Cosmic Cuttlefish" - Alpha amd64 (20180712)
SourcePackage: calamares
UpgradeStatus: No upgrade log present (probably fresh install)

[sudodus (nio-wiklund)]

I made this bug report to collect and upload relevant data about the hardware for this test (details about the NUC). Feel free to mark this a duplicate of bug #1781015.

[sudodus (nio-wiklund)]

Continued testing:

I installed the 'original' shellprocess.conf

---
$ cat /etc/calamares/modules/shellprocess.conf
dontChroot: true
timeout: 300
script:
  - "cp /cdrom/casper/vmlinuz @@ROOT@@/boot/vmlinuz-$(uname -r)"
  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ apt-cdrom add || exit 0"
  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ sed -e '/deb http/ s/^#*/#/' -i /etc/apt/sources.list || exit 0"
  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ apt update || exit 0"
  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ apt -y install grub-efi-amd64-bin || exit 0"
  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ sed -i 's/#deb/deb/' /etc/apt/sources.list || exit 0"
---

and got the following result (at 78%),

---
Error

Installation failed

External command failed to finish.
Command [ -d /sys/firmware/efi ] && chroot /tmp/calamares-root-v75xv4du apt-cdrom add || exit 0 failed to finish in 300 seconds. There was no output from the command.
---

[sudodus (nio-wiklund)]

I checked that Calameres can install Lubuntu Cosmic *in BIOS mode* in the NUC
from the same iso file 'cosmic-desktop-amd64.iso' dated July 12 2018.

It was successful, so this bug is specific for UEFI mode.