Build issue on Ubuntu 18.04

[miks]

What is the correct approach to build an image for rpi3 on Ubuntu? If I understand correctly then: 1) clone repository 2) cd kiosk_system_rpi3/example 3) export MIX_TARGET=rpi3 4) mix do deps.get, firmware, firmware.burn

on step 4. I'm getting:

qmake: could not find a Qt installation of ''
Makefile:7: recipe for target 'src/Makefile' failed
make: *** [src/Makefile] Error 1
could not compile dependency :webengine_kiosk, "mix compile" failed. You can recompile this dependency with "mix deps.compile webengine_kiosk", update it with "mix deps.update webengine_kiosk" or clean it with "mix deps.clean webengine_kiosk"
==> example
** (Mix) Could not compile with "make" (exit status: 2).
You need to have gcc and make installed. If you are using
Ubuntu or any other Debian-based system, install the packages
"build-essential". Also install "erlang-dev" package if not
included in your Erlang/OTP version. If you're on Fedora, run
"dnf group install 'Development Tools'".

But, if I understand correctly then I'm crossbuilding and there is no need to install qmake on host (Ubuntu 18.04). Am I right and missing something completely other?

[harmon25]

I am having a similar, or maybe related issue building on Ubuntu 18.04. Completely fresh VMs created specifically for compiling nerves firmware, and a physical box. (this has happened on multiple fresh installs this week)

I have been working on tweaking this systems GPU stack to optimize QTWebengine, as a result been rebuilding the firmware quite a bit - which takes a long time. I have run into this on all of my machines...

It is regarding the cross compilation of webengine_kiosk for the target.

Anyway here is the problem.

After successfully building the firmware, during the compilation of webengine_kiosk for the target (I assume) the following error is being thrown.

   /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5WebEngineWidgets.so /usr/lib/x86_
64-linux-gnu/libQt5WebEngineCore.so /usr/lib/x86_64-linux-gnu/libQt5Quick.so /usr/lib/x86_64-linux-gnu/libQt5Widgets.so
/usr/lib/x86_64-linux-gnu/libQt5Gui.so /usr/lib/x86_64-linux-gnu/libQt5QmlModels.so /usr/lib/x86_64-linux-gnu/libQt5WebC
hannel.so /usr/lib/x86_64-linux-gnu/libQt5Qml.so /usr/lib/x86_64-linux-gnu/libQt5Network.so /usr/lib/x86_64-linux-gnu/li
bQt5Core.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5Widgets.so /home/doug/.n
erves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5Multimedia.so /home/doug/.nerves/artifacts/kiosk_
system_rpi3-portable-1.9.1/staging/usr/lib/libQt5WebEngineCore.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portabl
e-1.9.1/staging/usr/lib/libQt5Quick.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/lib
Qt5Gui.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5QmlModels.so /home/doug/.n
erves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5WebChannel.so /home/doug/.nerves/artifacts/kiosk_
system_rpi3-portable-1.9.1/staging/usr/lib/libQt5Qml.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/st
aging/usr/lib/libQt5Network.so /home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib/libQt5Core.
so -latomic -lrt -ldl -L/home/doug/.nerves/artifacts/kiosk_system_rpi3-portable-1.9.1/staging/usr/lib -lGLESv2 -lpthread

arm-unknown-linux-gnueabihf-g++: error: /usr/lib/x86_64-linux-gnu/libQt5QmlModels.so: No such file or directory
Makefile:236: recipe for target 'kiosk' failed
make[1]: *** [kiosk] Error 1
make[1]: Leaving directory '/home/doug/projects/nrvs_ktchn_ksk/_build/rpi3_custom_dev/lib/webengine_kiosk/obj'
Makefile:23: recipe for target 'submake' failed
make: *** [submake] Error 2
could not compile dependency :webengine_kiosk, "mix compile" failed. You can recompile this dependency with "mix deps.co
mpile webengine_kiosk", update it with "mix deps.update webengine_kiosk" or clean it with "mix deps.clean webengine_kios
k"
==> nrvs_ktchn_ksk
** (Mix) Could not compile with "make" (exit status: 2).
You need to have gcc and make installed. If you are using
Ubuntu or any other Debian-based system, install the packages
"build-essential". Also install "erlang-dev" package if not
included in your Erlang/OTP version. If you're on Fedora, run
"dnf group install 'Development Tools'".

I am really not sure what it is doing looking at /usr/lib/x86_64-linux-gnu/ for that QT library.

arm-unknown-linux-gnueabihf-g++: error: /usr/lib/x86_64-linux-gnu/libQt5QmlModels.so: No such file or directory

The weird, and concerning thing, is the firmware builds the first time OK but then this starts happening and no amount of mix nerves.clean, or manually deleting ~/.nerves or _build or deps seems to help. Using a different branch of the kiosk_system_rpi3 or the hex published one makes no difference, the same error occurs.

I have a suspicion something is polluting the host in an unclear and not easily reversible way. Maybe it is related to something about Ubuntu 18.04 Server?

Any insight or help is much appreciated!

[harmon25]

Managed to sort this out with some help from @fhunleth on Slack.

When building this firmware, it leverages some host QT libraries. (sure)

The current nerves_br is shipping with qt 5.14. I think it is probably best to build this firmware on a system running the same version of QT to ensure compatibility.

On Ubuntu new versions of QT can be installed via this PPA

I think this issue can be closed.

To answer OPs question - YES, qmake does need to be installed on the host. (I am also a bit confused about this, but presume it is Qt related...)