basic_install exits without error despite multiple errors

[seriema]

@mitu @BuZz Here's the log for the latest RetroPie (558f25c) https://gist.github.com/seriema/05db8d60c11dc18d0285c6495b1b7dd7

The build succeeded, I think? I can't see an obvious error, and the roms folders are there as expected. I'm not sure what caused the failure last time, but it was likely a fluke. I'll see if I can provoke basic_install to fail and check the error code.

[seriema]

@BuZz I unintentionally got two failed installs so I'll share them as they had your exit code fix. They failed differently so at least it's something. :) The N64 emulator exited with 1 as expected, but Splashscreen exited with 0 (it didn't continue to install but I don't know how to tell when it's done done). Edit: It should end with Info: [message] on success?

1: basic_install exited with 1 when mupen64plus failed. Ran on Debian with amd64. See full log.

= = = = = = = = = = = = = = = = = = = = =
Building 'mupen64plus' : N64 emulator MUPEN64Plus
= = = = = = = = = = = = = = = = = = = = =
[snip]
make: Leaving directory '/home/pi/RetroPie-Setup/tmp/build/mupen64plus/mupen64plus-video-glide64mk2/projects/unix'
head: cannot open '/home/pi/RetroPie-Setup/tmp/build/mupen64plus/GLideN64/src/Revision.h' for reading: No such file or directory
current revision "50e83004"
last build revision
/home/pi/RetroPie-Setup/tmp/build/mupen64plus/GLideN64/projects/cmake /home/pi/RetroPie-Setup/tmp/build/mupen64plus /home/pi/RetroPie-Setup
CMake Error at CMakeLists.txt:1 (cmake_minimum_required):
  CMake 3.9 or higher is required.  You are running version 3.7.2


-- Configuring incomplete, errors occurred!
make: *** No targets specified and no makefile found.  Stop.
/home/pi/RetroPie-Setup/tmp/build/mupen64plus /home/pi/RetroPie-Setup
Removing additional swap
/home/pi/RetroPie-Setup
Could not successfully build mupen64plus - N64 emulator MUPEN64Plus (GLideN64/projects/cmake/plugin/Release/mupen64plus-video-GLideN64.so not found).
Errors:
Could not successfully build mupen64plus - N64 emulator MUPEN64Plus (GLideN64/projects/cmake/plugin/Release/mupen64plus-video-GLideN64.so not found).
The command '/bin/sh -c if [ "$(uname -m)" = 'x86_64' ]; then sudo ./retropie_packages.sh setup basic_install; fi' returned a non-zero code: 1

2: basic_install exited with 0 when splashscreen failed. Ran on Debian with arm32v7. See full log.

= = = = = = = = = = = = = = = = = = = = =
Configuring 'splashscreen' : Configure Splashscreen
= = = = = = = = = = = = = = = = = = = = =

/home/pi/RetroPie-Setup/scriptmodules/supplementary/splashscreen.sh: line 91: systemctl: command not found
/home/pi/RetroPie-Setup
Removing intermediate container c40e0a51fa8f
 ---> 3e4f12bb8360
[snip]
Successfully built 63739c10746d
Successfully tagged rc:docker-multiarch