I am very interested in improving the user-experience around precompilation and performance, may I ask why you are creating a sysimage from scratch?
> I would opt into prebuilt x86_64 generic binaries if Julia had them
The environment varial JULIA_CPU_TARGET [1] is what you are looking for, it controls what micro-architecture Julia emits for and supports multi-versioning.
As an example Julia is built with [2]:
generic;sandybridge,-xsaveopt,clone_all;haswell,-rdrnd,base(1)
> I would opt into prebuilt x86_64 generic binaries if Julia had them
The environment varial JULIA_CPU_TARGET [1] is what you are looking for, it controls what micro-architecture Julia emits for and supports multi-versioning.
As an example Julia is built with [2]: generic;sandybridge,-xsaveopt,clone_all;haswell,-rdrnd,base(1)
[1] https://docs.julialang.org/en/v1/manual/environment-variable...
[2] https://github.com/JuliaCI/julia-buildkite/blob/9c9f7d324c94...