To do: ignore indirect dependencies on CondaPkg

[cjdoris]

Currently CondaPkg reads CondaPkg.toml files for any package which depends directly or indirectly on CondaPkg.

Should we only read dependencies from direct dependents? I think yes.

Why? Indirect dependencies are not normally considered API - i.e. if PkgA depends on PkgB depends on CondaPkg, the PkgA should not rely on PkgB always depending on CondaPkg - it may decide to use something else in a future version. It also means that a breaking release of CondaPkg can safely change the format of CondaPkg.toml (or use a different file entirely) without needing to support the old format. I'm not anticipating any such breaking change, but you never know!

This would require simply changing the line

CondaPkg.jl/src/resolve.jl

Line 109 in baa6132

for env in [proj; [p.source for p in values(Pkg.dependencies())]]

to filter packages with p.is_direct_dep.

• This will be a breaking change, so is a good candidate for v1.
• The behaviour (either way) needs to be documented.
• Functions such as add and status should check if the project depends on CondaPkg and print a warning if not.