Variable substitution in snapcraft.yaml does not work in keys

[Lucy Llewellyn]

Currently the variables $SNAPCRAFT_PROJECT_NAME and $SNAPCRAFT_PROJECT_VERSION are substituted in the snapcraft.yaml when building. However, it is currently not possible to use these variables as part of the key side of the organize: key-value pairs.

Consider the following for the usage I envisaged but failed to achieve:

parts:
  alsa-lib:
    plugin: autotools
    source: ftp://ftp.alsa-project.org/pub/lib/alsa-lib-1.1.5.tar.bz2
    configflags:
    - --prefix=/usr
    - --sysconfdir=/etc
    - --libexec=/usr/lib
    - --libdir=/usr/lib
    - --localstatedir=/var
    - --with-configdir=/snap/$SNAPCRAFT_PROJECT_NAME/current/usr/share/alsa
    - --with-plugindir=/snap/$SNAPCRAFT_PROJECT_NAME/current/usr/lib/alsa-lib
    - --disable-static
    organize:
      snap/$SNAPCRAFT_PROJECT_NAME/current/usr/: usr/

With the above organize setting I expected the files under $SNAP/snap/<project-name>/current/usr to be moved to $SNAP/usr, however it does not work because the variable $SNAPCRAFT_PROJECT_NAME is not expanded in the key. The previous two instances of the same variable in the values of the list in configflags: do get correctly replaced. It seems that the substitution only works on values, and not keys, which is a problem when the keys are also freeform such as in the organize: block.

[Kyle Fazzari (kyrofa)]

Indeed, we need to replace these across the board (including in the `environment` keyword).

[Kyle Fazzari (kyrofa)]

Fix proposed here: https://github.com/snapcore/snapcraft/pull/2166

[Lucy Llewellyn (lucyllewy)]

Kyle, There's two potentially related bugs: #1746633 and #1766878