Does not detect changes in grouped targets

[dfalster]

This issue arose here, but I have seen similar behaviour elsewhere.

A nice feature of remake is the ability to group targets, e.g. if I'm writing a paper I might have a target called figures:

  figures:
    depends:
      - figures/plant.pdf
      - figures/patch.pdf
      - figures/emergent.pdf
      - figures/fitness.pdf
      - figures/schematic.pdf

I would have thought I could then use the figures target itself as a target, e.g.

  ms.pdf:
    command: latex_build("ms.tex", "refs.bib", clean=TRUE)
    depends:
      - figures

The problem is that when one of my figures changes, this change is not triggering a rebuild of ms.pdf. So as a result, I've been specifying the dependencies twice, which is not ideal. Eg.

  figures:
    depends:
      - figures/plant.pdf
      - figures/patch.pdf
      - figures/emergent.pdf
      - figures/fitness.pdf
      - figures/schematic.pdf

  ms.pdf:
    command: latex_build("ms.tex", "refs.bib", clean=TRUE)
    depends:
      - figures/plant.pdf
      - figures/patch.pdf
      - figures/emergent.pdf
      - figures/fitness.pdf
      - figures/schematic.pdf