Environment paths only work if link to my home directory?

snapcraft
1

Hi Folks,

I’m having problems with environment paths in my snap.

I need to manually declare certain paths for an app to work in my snap, but it’s the path itself that is troublesome.

For example, this app:

inspect:
      command: gst-inspect-1.0
      environment:
          LD_LIBRARY_PATH: $LD_LIBRARY_PATH:$SNAP/home/ubuntu/mysnaps/snaps/parts/tis/install/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/lib/tcam-0
          GST_PLUGIN_PATH: $SNAP/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/home/ubuntu/mysnaps/snaps/parts/tis/install/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/lib/tcam-0
          GST_PLUGIN_SYSTEM_PATH : $SNAP/usr/lib/aarch64-linux-gnu/gstreamer-1.0
          GST_PLUGIN_SCANNER: $SNAP/usr/lib/aarch64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner

As you can see, it has $SNAP/home/ubuntu and even goes so far as having aarch64-linux-gnu in the paths.

This is making it hard to build for different architectures, as I need a snap per architecture, and for the home paths, it means that I got to make sure that every computer it’s built on has it. I am assuming the build service wont work either.

Any help to make these paths functional, but build computer agnostic would be fantastic!

What am I doing wrong?

Thanks!

2

It seems strange to me that you need $SNAP/home/..., but that is presumably due to “other things” in your packaging recipe that you’ve not shared.

The architecture element is easy to address: ${SNAPCRAFT_ARCH_TRIPLET}

HTH

3

Thats for the SNAPCRAFT_ARCH_TRIPLET, I will give that a whirl.

I’m confused as to the $SNAP/home as well, expecially since my resulting file will work once installed on a another system that doesn’t have those files in my home directory.

But if I remove that path, my commands dont find the libraries needed.

Full snapcraft.yaml

    name: camera-dev
version: '1.02'
summary: Camera
description: |
  Snap to control kiosk camera.
grade: devel

architectures:
  - build-on: arm64
    run-on: arm64

confinement: devmode

base: core18

apps:
  stream:
      command: gst-launch-1.0 tcambin ! video/x-raw, format=GRAY8, width=640, height=480, framerate=60/1 ! videoconvert ! fbdevsink
      plugs: [camera,framebuffer]
      environment:
          LD_LIBRARY_PATH: $LD_LIBRARY_PATH:$SNAP/home/ubuntu/mysnaps/snaps/parts/tis/install/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/lib/tcam-0
          GST_PLUGIN_PATH: $SNAP/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/home/ubuntu/mysnaps/snaps/parts/tis/install/usr/lib/aarch64-linux-gnu/gstreamer-1.0:$SNAP/lib/tcam-0
          GST_PLUGIN_SYSTEM_PATH : $SNAP/usr/lib/aarch64-linux-gnu/gstreamer-1.0
          GST_PLUGIN_SCANNER: $SNAP/usr/lib/aarch64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner

parts:
  tis:
    source-type: git
    source: https://github.com/TheImagingSource/tiscamera
    plugin: cmake
    build-packages:
            - gstreamer1.0-tools
            - git
            - g++
            - pkg-config
            - uuid-dev
            - libudev-dev
            - libgstreamer1.0-dev
            - libgstreamer1.0-0
            - libgstreamer-plugins-base1.0-dev
            - libglib2.0-dev
            - libgirepository1.0-dev
            - libusb-1.0-0-dev
            - libzip-dev
            - python3-setuptools
            - libusb-1.0-0
            - libgl1
            - libglvnd0
            - libglx0
            - libgpm2
            - libslang2
            - uvcdynctrl # needed to load up uvc extension units
    stage-packages:
            - gstreamer1.0-tools
            - libusb-1.0-0
            - libgstreamer1.0-0
            - libgstreamer1.0-dev
            - libgstreamer-plugins-base1.0-0
            - gstreamer1.0-plugins-good
            - gstreamer1.0-plugins-bad
            - liborc-0.4-0
            - libpcre2-8-0
            - udev
            - uvcdynctrl # needed for udev rules
            - libgpm2
            - libslang2
            - libglu1-mesa
            - freeglut3
4

Any ideas on how I can get the /home/useraccount/ out of the environment variables?

Thanks!

5

What errors do you see if you omit /home/… from these paths?

6

when I run the .stream I get the error:

WARNING: erroneous pipeline: no element “tcambin”

Meaning that it can’t find the elements it needs to run the camera.

The crucial bit is in GST_PLUGIN_PATH.

Without $SNAP/home/ubuntu/mysnaps/snaps/parts/tis/install/usr/lib/aarch64-linux-gnu/gstreamer-1.0 it wont run, with it the camera starts up and works as it should.

7

This looks like it’s saving files into the snap using the path that they’re installed into during the build step. Specifically this means /home/ubuntu/mysnaps/snaps/parts/tis/install/usr. Try using override-build to move the files to the correct location:

parts:
  tis:
    ...
    override-build: |
      snapcraftctl build

      # the $SNAPCRAFT_PART_INSTALL is duplicated in the gstreamer-1.0 path,
      # so move the files back to the correct location
      mv $SNAPCRAFT_PART_INSTALL/$SNAPCRAFT_PART_INSTALL/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/gstreamer-1.0/* $SNAPCRAFT_PART_INSTALL/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/gstreamer-1.0/

      # remove the remaining duplicated paths
      rm -rf $SNAPCRAFT_PART_INSTALL/home
2 Likes
8

You guys are magic!

That was exactly what was needed!

1 Like