Steering issue #15

[lnicola]

Zulip meeting

• Fix the proc-macro-srv tests: Stop running the proc-macro-srv tests #12999
• Look into loading crates.io dependencies of libstd: Load crates.io dependencies of the standard library #7637
• Fix some of the issues resulting in server panics ("Broken Window" issues)
• Look into adding a feature to Cargo that makes the RUSTC_WRAPPER hack obsolete (Remove RUSTC_WRAPPER hack #12998)

Previous issue: #12805
Next issue: #13387