Fictional UUID created for non JLL package

[vchuravy]

In a local version of JuliaPackaging/Yggdrasil#4073 I am experimenting with adding a non jll dependency.
Thanks to @giordano who pointed me to the right place. We should look up the UUID instead of synthesizing a new one.

BinaryBuilder.jl/src/AutoBuild.jl

Line 1442 in 084d75b

project["deps"][depname] = string(jll_uuid(depname))

cc: @staticfloat

[staticfloat]

Heh, yeah. This is making use of the fact that JLLs all have deterministic UUIDs; so if you've got two different BBs generating JLLs that don't exist in the registry yet, they generate consistent UUIDs, etc...

But you're right, we should do a lookup in the registry first, and only do the hashing thing if it doesn't already have a match.