Success!I'm now running the Pharo 5.0, Pharo 6.0, and Moose 6.1 images without a hitch.Some hero has even fixed the libcairo name lookup issue in the Moose image. Now it's searching LD_LIBRARY_PATH and so I have added every shared library there in the wrapper script.I decided to manually write the SCCS version information directly in the package definition and update that with sed. This is the part that I need to maintain manually now:pharo-spur = pharo-vm-build rec {�� name = "pharo-vm-${version}";�� version = "git.${revision}";�� binary-basename = "pharo-vm";�� src = fetchFromGitHub {�� �� owner = "pharo-project";�� �� repo = "pharo-vm";�� �� rev = revision;�� �� sha256 = "114ydx015i8sg4xwy1hkb7vwkcxl93 h5vqz4bry46x2gnvsay7yh"; �� };�� # metadata compiled into the image:�� revision = "1c38b03fb043a2962f30f080db5b12 92b5b7badb"; �� sourceDate = "Wed Apr 12 19:25:16 2017 +0200";�� sourceURL ��= "https://github.com/pharo-project/pharo-vm ";};I will close my PR on the pharo-vm repo too because I ended up packaging the upstream source as-is without depending on any of those changes.Have to think about what's left... tidy up, test with the pharo-launcher image, test on OSX, push to nix upstream... something like that.Thanks for all the help !!Cheers,-Luke