Classic confinement and core_dynamic_linker

[Joseph Rushton Wakeling]

On 18/01/17 02:21, Sergio Schvezov wrote:
> The logic is still run, but the resulting binary in classic uses rpath and no dynamic loading so there is no resolution to a on-system library we can pick up. I guess we can do some magic, but it feels it might be either fragile or make the build process a lot slower. We will need to look into it, but not short term.

OK -- thanks for the explanation.  Completely understand the preference to 
require explicit staging of packages over potentially fragile automation.

Anyway, I had a go at tweaking my snap package as defined here:
https://github.com/WebDrake/ldc2.snap/pull/1/files
https://github.com/WebDrake/ldc2.snap/blob/a437ec17d50bdd767febebf5b617d7d3a716716b/snapcraft.yaml

... to use `classic` confinement and staging packages necessary for linking. 
I've posted the resulting `snapcraft.yaml` below.  The major diff apart from the 
`confinement` setting is the addition of these lines to the `ldc` part of the file:

     stage-packages:
     - libconfig++-dev
     - libphobos2-ldc-dev

When I run `snapcraft build`, however, everything builds and links fine, but 
_nothing_ gets staged (the `stage/` and `prime/` directories both remain empty). 
  I've tried the same thing while removing the `gcc`, `gcc-wrapper`, `libc6` and 
`libc6-dev` parts, with the same result.

Any thoughts on what could be the problem here?


--- snapcraft.yaml --------------------------------------------------

name: ldc2
version: "1.1.0-beta6"
summary: D compiler with LLVM backend
description: |
     LDC is a portable compiler for the D programming Language, with
     modern optimization and code generation capabilities.  It uses
     the official DMD compiler frontend to support the latest version
     of D2, and uses the LLVM Core libraries for code generation.
confinement: classic
grade: devel

apps:
   ldc2:
     command: ldc2
     plugs: [home]
   ldmd2:
     command: ldmd2
     plugs: [home]
   ldc-profdata:
     command: ldc-profdata
     plugs: [home]

parts:
   ldc:
     source: git://github.com/ldc-developers/ldc.git
     source-tag: v1.1.0-beta6
     plugin: cmake
     stage:
     - -etc/ldc2.conf
     build-packages:
     - build-essential
     - ldc
     - llvm-dev
     - libconfig++-dev
     - libedit-dev
     - zlib1g-dev
     stage-packages:
     - libconfig++-dev
     - libphobos2-ldc-dev
   ldc-config:
     plugin: dump
     source: ldc-config
     organize:
       ldc2.conf: etc/ldc2.conf

   gcc:
     plugin: nil
     stage-packages: [gcc]
     organize:
       usr/bin/gcc: usr/bin/gcc.real
   gcc-wrapper:
     plugin: dump
     source: gcc-wrapper
     organize:
       gcc.wrapper: usr/bin/gcc
   libc6:
     plugin: nil
     stage-packages: [libc6]
   libc6-dev:
     plugin: nil
     stage-packages: [libc6-dev]