Pkg.dependencies() triggers write_env_usage

[fonsp]

While debugging performance issues in https://github.com/JuliaPluto/PlutoSliderServer.jl we found that the Pkg.dependencies() call is quite heavy and was causing IO performance issues. Some profiling showed that write_env_usage was the cause.

I understand that more information on the write_env_usage performance problem would be really useful, but in the meantime I just wanted to ask:

Is it intentional that the call Pkg.dependencies() gets recorded in manifest_usage.toml? I feel like Pkg.dependencies() should not have any side effects. I also don't think it is necessary to record this as "manifest usage", since Pkg.dependencies() is mainly used by scripts and doesn't necessarily signal "usage" by a person.

Thanks!