Simultaneous support of 32-bit and 64-bit Julia versions

[tshort]

Using 32-bit and 64-bit versions of Julia on one computer is clunky with Julia v0.6 / Pkg2. When alternating, between versions, all packages have to be recompiled. In addition, if packages load binary libraries, you generally have to manually do a Pkg.build("MyPackage").

Does Pkg3 support this better?

This use case is mainly for testing different versions of Julia.

[StefanKarpinski]

Not currently, but we should change precompilation to be per-Julia-binary instead of per-Julia-version as it currently is. Not really a Pkg3-related issue, but everyone seems to enjoy discussion precompilation here, so I guess why not.

[KristofferC]

In addition, for packages with a build folders, we could do the same (two different paths for the same package, chose depending on Int size so building will use different folders).

[KristofferC]

Ideally, there should be a separate path, completely outside the source where stuff get built.

[KristofferC]

In addition, if packages load binary libraries, you generally have to manually do a Pkg.build("MyPackage").

Probably fixed with the artifact system. The precompilation thing is not something that can be changed from here.